diff --git a/game/builtin/item.go b/game/builtin/item.go
new file mode 100644
index 0000000..2ee78b9
--- /dev/null
+++ b/game/builtin/item.go
@@ -0,0 +1,48 @@
+package builtin
+
+import (
+	"minotaur/utils/huge"
+)
+
+func NewItem[ID comparable](id ID, count *huge.Int) *Item[ID] {
+	if count == nil || count.LessThan(huge.IntZero) {
+		panic(ErrItemCountException)
+	}
+	return &Item[ID]{
+		id:    id,
+		count: count,
+	}
+}
+
+type Item[ID comparable] struct {
+	id    ID
+	guid  int64
+	count *huge.Int
+}
+
+func (slf *Item[ID]) GetID() ID {
+	return slf.id
+}
+
+func (slf *Item[ID]) GetGuid() int64 {
+	return slf.guid
+}
+
+func (slf *Item[ID]) SetGuid(guid int64) {
+	slf.guid = guid
+}
+
+func (slf *Item[ID]) ChangeStackCount(count *huge.Int) *huge.Int {
+	if count.IsZero() {
+		return slf.count.Copy()
+	}
+	newCount := slf.count.Add(count)
+	if newCount.LessThan(huge.IntZero) {
+		slf.count = newCount.Set(huge.IntZero)
+	}
+	return slf.count
+}
+
+func (slf *Item[ID]) GetStackCount() *huge.Int {
+	return slf.count.Copy()
+}
diff --git a/game/builtin/item_errors.go b/game/builtin/item_errors.go
new file mode 100644
index 0000000..e036a3d
--- /dev/null
+++ b/game/builtin/item_errors.go
@@ -0,0 +1,5 @@
+package builtin
+
+var (
+	ErrItemCountException = "the number of items cannot be empty and must be a positive integer"
+)
diff --git a/game/item.go b/game/item.go
index 9e9dfe6..a1ff591 100644
--- a/game/item.go
+++ b/game/item.go
@@ -1,9 +1,17 @@
 package game
 
+import "minotaur/utils/huge"
+
 // Item 物品接口定义
 type Item[ID comparable] interface {
 	// GetID 获取物品id
 	GetID() ID
-	// GetCount 获取物品数量
-	GetCount() int
+	// GetGuid 获取物品guid
+	GetGuid() int64
+	// SetGuid 设置物品guid
+	SetGuid(guid int64)
+	// ChangeStackCount 改变物品堆叠数量，返回新数量
+	ChangeStackCount(count *huge.Int) *huge.Int
+	// GetStackCount 获取物品堆叠数量
+	GetStackCount() *huge.Int
 }