diff --git a/internal/infra/models/medication.go b/internal/infra/models/medication.go
new file mode 100644
index 0000000..05dcbce
--- /dev/null
+++ b/internal/infra/models/medication.go
@@ -0,0 +1,68 @@
+package models
+
+import (
+	"time"
+
+	"gorm.io/datatypes"
+	"gorm.io/gorm"
+)
+
+/*
+	所有与药品、疫苗和用药记录相关的模型
+*/
+
+// MedicationType 定义了兽药的类型
+type MedicationType string
+
+const (
+	Powder    MedicationType = "粉剂"
+	Injection MedicationType = "针剂"
+	Vaccine   MedicationType = "疫苗"
+)
+
+// MedicationCategory 定义了兽药的种类
+type MedicationCategory string
+
+const (
+	Tetracycline      MedicationCategory = "四环素类"
+	Sulfonamide       MedicationCategory = "磺胺类"
+	Penicillin        MedicationCategory = "青霉素类"
+	Macrolide         MedicationCategory = "大环内酯类"
+	Quinolone         MedicationCategory = "喹诺酮类"
+	Anthelmintic      MedicationCategory = "驱虫药"
+	Disinfectant      MedicationCategory = "消毒药"
+	BiologicalProduct MedicationCategory = "生物制品"
+)
+
+// MixType 定义了粉剂药物该如何混合
+type MixType string
+
+const (
+	MixFeed  = "饲料加药"
+	MixWater = "水中加药"
+)
+
+// PowderInstructions 定义了粉剂使用说明.
+// 在程序中, 可以将 Medication.Instructions 字段反序列化为此结构进行操作.
+type PowderInstructions struct {
+	// 出栏前停药期
+	WithdrawalPeriod time.Duration `json:"withdrawal_period"`
+	// 拌料使用计量, 每千克体重用多少克药, 单位: g/kg
+	BodyWeightDosageUsed float64 `json:"body_weight_dosage_used"`
+	// 拌料使用剂量, 每升水加多少克药或每千克饲料干重加多少克药, 单位: g/kg(L)
+	MixDosageUsed float64 `json:"mix_dosage_used"`
+	// 拌料使用方式, 兑水/拌料
+	MixType MixType `json:"mix_type"`
+}
+
+// Medication 定义了兽药/疫苗的基本信息模型
+type Medication struct {
+	gorm.Model
+	Name                          string             `gorm:"size:100;not null;comment:药品名称" json:"name"`
+	Type                          MedicationType     `gorm:"size:20;not null;comment:兽药类型 (粉剂, 针剂, 疫苗)" json:"type"`
+	Category                      MedicationCategory `gorm:"size:30;not null;comment:兽药种类 (四环素类, 磺胺类等)" json:"category"`
+	DosagePerUnit                 float64            `gorm:"size:50;comment:一份药物的计量 (针剂计量单位为毫升, 粉剂为克)" json:"dosage_per_unit"`
+	ActiveIngredientConcentration float64            `gorm:"size:50;comment:有效成分含量百分比" json:"active_ingredient_concentration"`
+	Manufacturer                  string             `gorm:"size:100;comment:生产厂家" json:"manufacturer"`
+	Instructions                  datatypes.JSON     `gorm:"type:jsonb;comment:使用说明" json:"instructions"`
+}