Objective To observe the clinical characteristics of patients with macular branch retinal vein occlusion (MBRVO) and the changes of the area of foveal avascular zone (FAZ).Methods The data of 69 eyes of 69 patients with MBRVO, who had been diagnosed by ophthalmoscopy, slit-lamp examination and fluoresce in angiography, were retrospectively studied. The relationship of locations between artery and vein on the obstructive site, and the characteristics of fundus pictures, retinal vasculature changes and the complications were analyzed. In 69 patients with MBRVO, 36 had the course of disease for more than 3-6 months, of whom the area of FAZ was compared with that of 30 healthy people.Results In 69 patients, superior MBRVO occurred in 45 eyes (65.22%), and inferior MBRVO occurred in 24 eyes (34.78%). Most of the arteries were anterior to the veins at the obstructive site. Four clinical types of MBRVO were found, and the main complication was macular edema. There was a significant difference in area of FAZ between patients with MBRVO and healthy people (P＜0.05). Conclusion There are several clinical characteristics of MBRVO with different manifestations. The area of FAZ of patients with MBRVO is obviously lager than that of the healthy people. (Chin J Ocul Fundus Dis，2003，19：269-332)