AIM:To analyze the reason for different of visual acuity after phacoemulsification surgery in treating diabetic cataract and senile cataract patients. METHODS:After operation,diabetic cataract patients (60 eyes,diabetic group) and senile cataract patients(60 eyes,non-diabetic group) underwent the fundus fluorescein angiography(FFA) on the postoperative week 1 and 2,month 3 and 6. RESULTS:There was significantly difference in improvement of visual acuity between non-diabetic group and diabetic group after phacoemulsification.Macular edema in diabetic group was significantly higher than that in non-diabetic group. CONCLUSION:Macular edema and diabetic retinopathy are the main reason for affecting visual acuity in patients with diabetic cataract after phacoemulsification.