diff --git a/src/main/java/org/jcnc/snow/compiler/parser/ast/ASTPrinter.java b/src/main/java/org/jcnc/snow/compiler/parser/ast/ASTPrinter.java
index df2018b..b35f377 100644
--- a/src/main/java/org/jcnc/snow/compiler/parser/ast/ASTPrinter.java
+++ b/src/main/java/org/jcnc/snow/compiler/parser/ast/ASTPrinter.java
@@ -56,12 +56,19 @@ public class ASTPrinter {
             }
             case AssignmentNode(String variable, ExpressionNode value) ->
                     System.out.println(pad + variable + " = " + value);
-            case IfNode(ExpressionNode condition, List<StatementNode> thenBranch) -> {
+            case IfNode(ExpressionNode condition, List<StatementNode> thenBranch, List<StatementNode> elseBranch) -> {
                 System.out.println(pad + "if " + condition);
                 for (StatementNode stmt : thenBranch) {
                     print(stmt, indent + 1);
                 }
+                if (!elseBranch.isEmpty()) {
+                    System.out.println(pad + "else");
+                    for (StatementNode stmt : elseBranch) {
+                        print(stmt, indent + 1);
+                    }
+                }
             }
+
             case LoopNode(
                     StatementNode initializer, ExpressionNode condition, StatementNode update, List<StatementNode> body
             ) -> {
diff --git a/src/main/java/org/jcnc/snow/compiler/parser/statement/IfStatementParser.java b/src/main/java/org/jcnc/snow/compiler/parser/statement/IfStatementParser.java
index fcf8d8c..d21e128 100644
--- a/src/main/java/org/jcnc/snow/compiler/parser/statement/IfStatementParser.java
+++ b/src/main/java/org/jcnc/snow/compiler/parser/statement/IfStatementParser.java
@@ -12,65 +12,75 @@ import java.util.ArrayList;
 import java.util.List;
 
 /**
- * if 语句解析器，支持：
- * <pre>{@code
- * if condition then
- *   statements...
- * else
- *   statements...
+ * 解析 if 语句：
+ *
+ * 支持格式：
+ * if <condition> then
+ *   <then-statements>
+ * [else
+ *   <else-statements>]
  * end if
- * }</pre>
  */
 public class IfStatementParser implements StatementParser {
 
     @Override
     public IfNode parse(ParserContext ctx) {
-        var ts = ctx.getTokens();
+        var ts = ctx.getTokens(); // 获取 Token 流管理器
 
-        ts.expect("if");
+        ts.expect("if"); // 消费 "if" 关键字
 
-        // 解析条件表达式
-        var cond = new PrattExpressionParser().parse(ctx);
+        // 使用 Pratt 解析器解析布尔表达式或其他条件表达式
+        var condition = new PrattExpressionParser().parse(ctx);
 
+        // 消费 "then" 关键字和随后的换行符
         ts.expect("then");
         ts.expectType(TokenType.NEWLINE);
 
+        // 准备容器存储 then 和 else 分支的语句
         List<StatementNode> thenBranch = new ArrayList<>();
         List<StatementNode> elseBranch = new ArrayList<>();
 
-        // --- THEN 分支 ---
+        // -------------------
+        // 解析 THEN 分支语句
+        // -------------------
         while (true) {
             Token peek = ts.peek();
 
-            // 跳过空行
+            // 忽略空行
             if (peek.getType() == TokenType.NEWLINE) {
                 ts.next();
                 continue;
             }
 
+            // 检测是否进入 else 或 end，跳出 then 区块
             if (peek.getType() == TokenType.KEYWORD &&
                     (peek.getLexeme().equals("else") || peek.getLexeme().equals("end"))) {
                 break;
             }
 
+            // 提取关键词，交由 StatementParserFactory 派发对应解析器
             String keyword = peek.getType() == TokenType.KEYWORD ? peek.getLexeme() : "";
             StatementNode stmt = StatementParserFactory.get(keyword).parse(ctx);
             thenBranch.add(stmt);
         }
 
-        // --- ELSE 分支 ---
+        // -------------------
+        // 解析 ELSE 分支语句
+        // -------------------
         if (ts.peek().getLexeme().equals("else")) {
-            ts.next(); // consume 'else'
-            ts.expectType(TokenType.NEWLINE);
+            ts.next(); // 消费 "else"
+            ts.expectType(TokenType.NEWLINE); // 消费换行
 
             while (true) {
                 Token peek = ts.peek();
 
+                // 忽略空行
                 if (peek.getType() == TokenType.NEWLINE) {
                     ts.next();
                     continue;
                 }
 
+                // "end" 关键字表示 else 块结束
                 if (peek.getType() == TokenType.KEYWORD && peek.getLexeme().equals("end")) {
                     break;
                 }
@@ -81,10 +91,12 @@ public class IfStatementParser implements StatementParser {
             }
         }
 
+        // 统一消费 "end if" 和其后的换行
         ts.expect("end");
         ts.expect("if");
         ts.expectType(TokenType.NEWLINE);
 
-        return new IfNode(cond, thenBranch, elseBranch);
+        // 构造 AST 节点，返回 IfNode 包含条件、then 分支、else 分支
+        return new IfNode(condition, thenBranch, elseBranch);
     }
 }