diff --git a/src/error/error.rs b/src/error/error.rs
index 66f9f3d..0a26933 100644
--- a/src/error/error.rs
+++ b/src/error/error.rs
@@ -58,7 +58,8 @@ impl Error {
                     | ParseError::NotClosedStmt(loc, ..)
                     | ParseError::OperatorAfterRetrun(loc, ..)
                     | ParseError::NotIdent(loc, ..)
-                    | ParseError::NotAssign(loc, ..) => loc.loc.clone(),
+                    | ParseError::NotAssign(loc, ..)
+                    | ParseError::NotDefinitionVar(loc, ..) => loc.loc.clone(),
                     ParseError::Eof => Loc::new(input.len() as u8, input.len() as u8 + 1),
                 };
                 (e, loc)
diff --git a/src/fmt/fmt.rs b/src/fmt/fmt.rs
index 0bde1d7..db0e745 100644
--- a/src/fmt/fmt.rs
+++ b/src/fmt/fmt.rs
@@ -66,6 +66,11 @@ impl fmt::Display for ParseError {
             ParseError::NotAssign(tok) => {
                 write!(f, "{}: Expected assign but got {}.", tok.loc, tok.value)
             }
+            ParseError::NotDefinitionVar(tok) => write!(
+                f,
+                "{}: Expected definition var but not detected. Failed ident is {}",
+                tok.loc, tok.value
+            ),
             ParseError::Eof => write!(f, "Expected token, but not detected."),
         }
     }
diff --git a/src/lib.rs b/src/lib.rs
index 3241b32..31b3c9d 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -8,3 +8,4 @@ pub mod parser;
 pub mod simplified;
 pub mod tests;
 pub mod token;
+pub mod var;
diff --git a/src/node_arr/node_arr.rs b/src/node_arr/node_arr.rs
index a863ef2..5f0574d 100644
--- a/src/node_arr/node_arr.rs
+++ b/src/node_arr/node_arr.rs
@@ -1,11 +1,24 @@
 use super::super::node::node::*;
 use super::super::parser::error::*;
 use super::super::token::token::*;
+use super::super::var::var::*;
 
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct NodeArr {
     pub node_st_vec: Vec<NodeSt>,
     pub ret_node_st: NodeSt,
+    pub l: Vec<Var>,
+}
+
+impl NodeArr {
+    pub fn find_l(s: String, vv: Vec<Var>) -> Option<Var> {
+        for v in vv {
+            if v.s == s {
+                return Some(v);
+            }
+        }
+        None
+    }
 }
 
 impl NodeArr {
@@ -13,29 +26,52 @@ impl NodeArr {
         Self {
             node_st_vec: v.to_owned(),
             ret_node_st: v.to_owned().last().unwrap().to_owned(),
+            l: vec![],
         }
     }
 
     pub fn w_parser(vt: Vec<Token>) -> Result<Self, ParseError> {
         let mut vti = vt.iter().peekable();
-        let mut n = vec![];
+        let mut nv = vec![];
+        let mut l: Vec<Var> = vec![];
 
         while vti.peek() != None {
-            n.push(match NodeSt::parser(&mut vti) {
-                Ok(n) => {
-                    // println!("n: {:?}", n);
-                    if n.c.value == NodeKind::Return && vti.peek() != None {
-                        return Err(ParseError::OperatorAfterRetrun(
-                            vti.next().unwrap().to_owned(),
-                        ));
+            nv.push(match NodeSt::parser(&mut vti) {
+                Ok(n) => match n.c.value {
+                    NodeKind::Return => {
+                        if vti.peek() != None {
+                            return Err(ParseError::OperatorAfterRetrun(
+                                vti.next().unwrap().to_owned(),
+                            ));
+                        }
+                        n
+                    }
+                    NodeKind::Assign => {
+                        let s = match n.to_owned().lhs.unwrap().lhs.unwrap().c.value {
+                            NodeKind::Ident(s) => s,
+                            _ => unreachable!(),
+                        };
+                        let n = n.lhs.as_ref().unwrap().as_ref().to_owned();
+                        let v = Var::new(s, n);
+                        l.push(v);
+                        continue;
                     }
-                    n
-                }
+                    NodeKind::Ident(s) => match Self::find_l(s, l.to_owned()) {
+                        Some(v) => v.n,
+                        None => {
+                            return Err(ParseError::NotDefinitionVar(
+                                vti.next().unwrap().to_owned(),
+                            ))
+                        }
+                    },
+                    _ => n,
+                },
                 Err(e) => return Err(e),
             });
         }
 
-        let a = Self::new(n);
+        let mut a = Self::new(nv);
+        a.l = l;
         Ok(a)
     }
 }
diff --git a/src/parser/error.rs b/src/parser/error.rs
index 439d439..1fb4401 100644
--- a/src/parser/error.rs
+++ b/src/parser/error.rs
@@ -10,6 +10,7 @@ pub enum ParseError {
     OperatorAfterRetrun(Token),
     NotIdent(Token),
     NotAssign(Token),
+    NotDefinitionVar(Token),
     // UnexpectedToken(Token),
     // NotExpression(Token),
     // UnclosedOpenParen(Token),
diff --git a/src/tests/parser/tests.rs b/src/tests/parser/tests.rs
index c8e64a0..74f3725 100644
--- a/src/tests/parser/tests.rs
+++ b/src/tests/parser/tests.rs
@@ -55,37 +55,13 @@ fn evaluation_final_value_test() {
 
 #[test]
 fn parser_assign_test() {
-    let t = Token::tokenize("int a = 3;").unwrap();
+    let t = Token::tokenize("int a = 3; 1").unwrap();
     let l = NodeArr::w_parser(t).unwrap().ret_node_st;
     let e = {
         NodeSt {
-            c: Annot {
-                value: NodeKind::Assign,
-                loc: Loc { f: 7, e: 8 },
-            },
-            lhs: Some(Box::new(NodeSt {
-                c: Annot {
-                    value: NodeKind::Int,
-                    loc: Loc { f: 0, e: 3 },
-                },
-                lhs: Some(Box::new(NodeSt {
-                    c: Annot {
-                        value: NodeKind::Ident("a".to_string()),
-                        loc: Loc { f: 4, e: 6 },
-                    },
-                    lhs: None,
-                    rhs: None,
-                })),
-                rhs: None,
-            })),
-            rhs: Some(Box::new(NodeSt {
-                c: Annot {
-                    value: NodeKind::Num(3),
-                    loc: Loc { f: 10, e: 11 },
-                },
-                lhs: None,
-                rhs: None,
-            })),
+            c: Node::number(1, Loc::new(14, 15)),
+            lhs: None,
+            rhs: None,
         }
     };
     assert_eq!(e, l)
diff --git a/src/var/mod.rs b/src/var/mod.rs
new file mode 100644
index 0000000..9b21e5b
--- /dev/null
+++ b/src/var/mod.rs
@@ -0,0 +1 @@
+pub mod var;
diff --git a/src/var/var.rs b/src/var/var.rs
new file mode 100644
index 0000000..864e8e5
--- /dev/null
+++ b/src/var/var.rs
@@ -0,0 +1,20 @@
+use super::super::node::node::*;
+
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub struct Var {
+    pub s: String,
+    pub n: NodeSt,
+}
+
+impl Var {
+    pub fn new(s: String, n: NodeSt) -> Self {
+        Self { s, n }
+    }
+
+    pub fn default() -> Self {
+        Self {
+            s: String::new(),
+            n: NodeSt::default(),
+        }
+    }
+}
diff --git a/test.sh b/test.sh
index f8e8408..3129bee 100644
--- a/test.sh
+++ b/test.sh
@@ -50,6 +50,8 @@ assert 3 '(1*2>=3-(2*1))+2;' simplified
 assert 4 '4'
 assert 3 '2; 3'
 assert 4 'return 4;'
+assert 1 'int a = 3; 1;'
+assert 2 'int a = 3; return 2;'
 
 echo "------------------------------"
 echo "All test passed!"