diff --git a/XUnitTester/LifecycleHook.cs b/XUnitTester/LifecycleHook.cs
new file mode 100644
index 0000000..69009ed
--- /dev/null
+++ b/XUnitTester/LifecycleHook.cs
@@ -0,0 +1,34 @@
+using System.Collections.Generic;
+using GeminiLab.Core2.CommandLineParser;
+using GeminiLab.Core2.CommandLineParser.Default;
+using Xunit;
+
+namespace XUnitTester {
+    public static class LifecycleHook {
+        class HookedOption {
+            public List<string> Queue { get; set; } = new List<string>();
+
+            [PreParsing]
+            public void PreParsing() {
+                Queue.Add("pre");
+            }
+
+            [PostParsing]
+            public void PostParsing() {
+                Queue.Add("post");
+            }
+
+            [ShortOption('z', OptionParameter.Required)]
+            public void Zulu(string z) {
+                Queue.Add($"z:{z}");
+            }
+        }
+
+        [Fact]
+        public static void LifecycleHookTest() {
+            var options = CommandLineParser<HookedOption>.DoParse("-zzulu");
+
+            Assert.Equal(new string[] { "pre", "z:zulu", "post" }, options.Queue);
+        }
+    }
+}
diff --git a/src/GeminiLab.Core2.CommandLineParser/CommandLineParser.cs b/src/GeminiLab.Core2.CommandLineParser/CommandLineParser.cs
index c05fc6c..b266e3e 100644
--- a/src/GeminiLab.Core2.CommandLineParser/CommandLineParser.cs
+++ b/src/GeminiLab.Core2.CommandLineParser/CommandLineParser.cs
@@ -21,6 +21,7 @@ public static T DoParse(params string[] args) {
 
         private List<IOptionCategory>                      _optionCategories  = null!;
         private List<(Type ExceptionType, object Handler)> _exceptionHandlers = null!;
+        private List<IParsingHook>                         _hooks             = null!;
 
         [Obsolete("Use method 'Parse' instead")]
         public T ParseFromSpan(ReadOnlySpan<string> args) {
@@ -172,6 +173,7 @@ private void EvaluateMetaInfo() {
 
             _optionCategories = new List<IOptionCategory>();
             _exceptionHandlers = new List<(Type ExceptionType, object Handler)>();
+            _hooks = new List<IParsingHook>();
 
             var attributes = GetAttributes();
 
@@ -211,6 +213,10 @@ private void EvaluateMetaInfo() {
                     if (ifType == typeof(IOptionCategory)) {
                         _optionCategories.Add((IOptionCategory) instance);
                     }
+
+                    if (ifType == typeof(IParsingHook)) {
+                        _hooks.Add((IParsingHook) instance);
+                    }
                 }
             }
         }
@@ -225,6 +231,8 @@ public T Parse(params string[] args) {
             int ptr = 0;
             var rv = new T();
 
+            _hooks.ForEach(h => h.OnParsingEvent(ParsingEvent.PreParsing, rv));
+
             while (ptr < len) {
                 var current = workplace[ptr..];
                 int consumed = 0;
@@ -267,6 +275,8 @@ public T Parse(params string[] args) {
                 ptr += consumed;
             }
 
+            _hooks.ForEach(h => h.OnParsingEvent(ParsingEvent.PostParsing, rv));
+
             return rv;
         }
 
@@ -277,6 +287,7 @@ private void LoadDefaultConfigs() {
             Use<TailArgumentsCategory, TailArgumentsConfig>(new TailArgumentsConfig());
             Use<NonOptionArgumentCategory>();
 
+            Use<LifecycleHookComponent>();
             Use<UnknownOptionHandlerComponent>();
         }
 
diff --git a/src/GeminiLab.Core2.CommandLineParser/Custom/IParsingHook.cs b/src/GeminiLab.Core2.CommandLineParser/Custom/IParsingHook.cs
new file mode 100644
index 0000000..07f9929
--- /dev/null
+++ b/src/GeminiLab.Core2.CommandLineParser/Custom/IParsingHook.cs
@@ -0,0 +1,10 @@
+namespace GeminiLab.Core2.CommandLineParser.Custom {
+    public enum ParsingEvent {
+        PreParsing,
+        PostParsing,
+    }
+    
+    public interface IParsingHook {
+        void OnParsingEvent(ParsingEvent parsingEvent, object target);
+    }
+}
diff --git a/src/GeminiLab.Core2.CommandLineParser/Default/LifecycleHookAttributes.cs b/src/GeminiLab.Core2.CommandLineParser/Default/LifecycleHookAttributes.cs
new file mode 100644
index 0000000..9690f05
--- /dev/null
+++ b/src/GeminiLab.Core2.CommandLineParser/Default/LifecycleHookAttributes.cs
@@ -0,0 +1,11 @@
+using System;
+using GeminiLab.Core2.CommandLineParser.Custom;
+
+namespace GeminiLab.Core2.CommandLineParser.Default {
+    [AttributeUsage(AttributeTargets.Method, AllowMultiple = true)]
+    public class PreParsingAttribute : ParsingAttribute { }
+
+
+    [AttributeUsage(AttributeTargets.Method, AllowMultiple = true)]
+    public class PostParsingAttribute : ParsingAttribute { }
+}
diff --git a/src/GeminiLab.Core2.CommandLineParser/Default/LifecycleHookComponent.cs b/src/GeminiLab.Core2.CommandLineParser/Default/LifecycleHookComponent.cs
new file mode 100644
index 0000000..99d81c3
--- /dev/null
+++ b/src/GeminiLab.Core2.CommandLineParser/Default/LifecycleHookComponent.cs
@@ -0,0 +1,27 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Reflection;
+using GeminiLab.Core2.CommandLineParser.Custom;
+
+namespace GeminiLab.Core2.CommandLineParser.Default {
+    public class LifecycleHookComponent : IParsingHook, IAttributeCategory<PreParsingAttribute>, IAttributeCategory<PostParsingAttribute> {
+        private MethodInfo? _pre, _post;
+
+        public void OnParsingEvent(ParsingEvent parsingEvent, object target) {
+            (parsingEvent switch {
+                ParsingEvent.PreParsing  => _pre,
+                ParsingEvent.PostParsing => _post,
+                _                        => null,
+            })?.Invoke(target, Array.Empty<object>());
+        }
+
+        IEnumerable<IAttributeCategory<PreParsingAttribute>.MemberWithAttribute> IAttributeCategory<PreParsingAttribute>.Options {
+            set { _pre = value.Select(mwa => mwa.Target).OfType<MethodInfo>().FirstOrDefault(); }
+        }
+
+        IEnumerable<IAttributeCategory<PostParsingAttribute>.MemberWithAttribute> IAttributeCategory<PostParsingAttribute>.Options {
+            set { _post = value.Select(mwa => mwa.Target).OfType<MethodInfo>().FirstOrDefault(); }
+        }
+    }
+}
diff --git a/src/GeminiLab.Core2.CommandLineParser/Default/UnknownOptionHandlerAttribute.cs b/src/GeminiLab.Core2.CommandLineParser/Default/UnknownOptionHandlerAttribute.cs
index 6365002..e044b55 100644
--- a/src/GeminiLab.Core2.CommandLineParser/Default/UnknownOptionHandlerAttribute.cs
+++ b/src/GeminiLab.Core2.CommandLineParser/Default/UnknownOptionHandlerAttribute.cs
@@ -2,6 +2,6 @@
 using GeminiLab.Core2.CommandLineParser.Custom;
 
 namespace GeminiLab.Core2.CommandLineParser.Default {
-    [AttributeUsage(SupportedTargets, AllowMultiple = true)]
+    [AttributeUsage(AttributeTargets.Method, AllowMultiple = true)]
     public class UnknownOptionHandlerAttribute : ParsingAttribute { }
 }