Objective: To evaluate the efficacy in patients with macular edema due to branch retinal vein occlusion (BRVO) treated with intravitreal anti-VEGF drug. Methods: In this retrospective study, 32 eyes of 31 patients with BRVO combined with macular edema at Joint Shantou international eye center of Shantou University and TheChinese University of Hong Kong during January 2017 to December 2018 were enrolled in this study. All the affected eyes received intravitreal anti-VEGF drug injections. BCVA (best corrective visual acuity) and optical coherence tomography angiography (OCTA) were performed before and one month after intravitreal anti-VEGF drug injections. Foveal macular thickness (FMT), macular blood flow density was measured in all eyes and compared. Results: The BCVA before therapy was (0.77±0.46) LogMAR and increased to (0.46±0.30) LogMAR in one month after therapy, which showed a statistical difference (P<0.001). The FMT, foveal superficial vascular plexus flow density and para foveal superficial vascular plexus flow density before therapy were (521.44±190.27) μm, (21.85±6.17)% and (46.29±2.70)%, respectively. The FMT, foveal superficial vascular plexus flow density and para foveal superficial vascular plexus flow density decreased to (242.13±86.02) μm, (18.40±5.18)% and (44.75±3.40)%, respectively. There was significant statistical difference for them (P<0.001). Conclusion: Intravitreal injection of anti-VEGF is effective in the treatment of BRVO combined with macular edema. OCTA can effectively evaluate the clinical efficacy of anti-VEGF in the treatment of BRVO combined with macular edema.