Abstract: Objective: To Investigate the ocular toxicity related to tamoxifen therapy to breast cancer. Methods: 47 cases of breast cancer underwent mastectomy took 20～60 mg per day of tamoxifen Visual acuity was measured with Snellen chart Intensive ophthalmic examinations were performed, including slit lamp, ophthalmoscope, funds fluorescein angiography （FFA）, automated perimeter Any Ocular toxicity was recorded and analyzed. Results: Mean follow up period was 45 months （range, 2 to 79 moths） Decline of visual acuity in 2 cases （3 eyes） out of 47 cases （94 eyes） （4 2%） happened in 2 moths and 9 moths after taking tamoxifen, respectively Perimacular refraction yellow white deposits in retina and macular edema were found at that time FFA demonstrated the fluorescein leakage in macular and fluorescein block in deposit dots Total dosages of tamoxifen at that time were 5 4 g and 12 6 g, respectively Visual acuity improved, the number of deposites reduced and macular edema resolved following taper of tamoxifen dosages. Conclusion: Tamoxifen can lead reversible retinopathy at lower coincidence Linear relationship between tamoxife dosage and ocular toxicity cannot be conformed.