diff --git a/lexer/token.go b/lexer/token.go
new file mode 100644
index 0000000..fb42455
--- /dev/null
+++ b/lexer/token.go
@@ -0,0 +1,111 @@
+package lexer
+
+import (
+	"errors"
+	"fmt"
+	"io"
+)
+
+var (
+	EOF = io.EOF // EOF marker
+)
+
+// Token type
+type TokenType int
+
+const (
+	TokenError TokenType = iota
+)
+
+// Token Position
+type TokenPosition struct {
+	Line int
+	Row  int
+}
+
+// Token
+type Token interface {
+	Type() TokenType
+	String() string
+	Position() TokenPosition
+}
+
+type token struct {
+	typ TokenType
+	pos TokenPosition
+	val string
+}
+
+func NewToken(typ TokenType, val []rune, pos TokenPosition) Token {
+	return &token{
+		typ: typ,
+		val: string(val),
+		pos: pos,
+	}
+}
+
+func (t token) Type() TokenType {
+	return t.typ
+}
+
+func (t token) Position() TokenPosition {
+	return t.pos
+}
+
+func (t token) String() string {
+	return t.val
+}
+
+// ErrorToken
+type ErrorToken interface {
+	Token
+	Error() string
+	Unwrap() error
+}
+
+type errorToken struct {
+	token
+	err error
+}
+
+func NewErrorToken(err error, pos TokenPosition) ErrorToken {
+	return &errorToken{
+		token: token{
+			typ: TokenError,
+			val: err.Error(),
+			pos: pos,
+		},
+		err: err,
+	}
+}
+
+func (t errorToken) Error() string {
+	return t.err.Error()
+}
+
+func (t errorToken) Unwrap() error {
+	return t.err
+}
+
+// SyntaxErrorToken
+type SyntaxErrorToken struct {
+	ErrorToken
+
+	Cursor int
+	Buffer string
+}
+
+func NewSyntaxErrorToken(msg string, pos TokenPosition, cur int, buffer []rune) *SyntaxErrorToken {
+	s := fmt.Sprintf("Syntax Error at %v.%v+%v", pos.Line, pos.Row, cur)
+
+	if len(msg) > 0 {
+		s = fmt.Sprintf("%s: %s", s, msg)
+	}
+
+	return &SyntaxErrorToken{
+		ErrorToken: NewErrorToken(errors.New(s), pos),
+
+		Cursor: cur,
+		Buffer: string(buffer),
+	}
+}