Objective To observe the axial length and anterior chamber depth in eyes with branch retinal vein occlusion (BRVO). Methods Randomly selected 90 eyes of forty-five patients with BRVO were enrolled in this study. There were 25 males and 20 females. The mean age was (46.22±13.45) years. All the patients were underwent examination of visual acuity, slit-lamp microscope, indiophthalmoscope, fundus color photography and fundus fluorescence angiography (FFA). Randomly selected 45 healthy individuals for control group, including 28 males and 17 females. The mean age was (48.24±15.77) years. The axial lengths and anterior chamber depths of affected and fellow eyes of BRVO patients and the eyes of controls were measured using IOL Master. The data were compared by the two sample paired t test. Results The mean axial length of the affected eyes in the BRVO group was (22.69±0.99) mm, and that of the fellow eyes group was (22.78±1.24) mm. The difference in axial length between the affected eyes and fellow eyes in the BRVO group was not significant (t=0.355, P＞0.05). The mean axial length of the right eyes in the control group was (23.38±1.32) mm, and that of the left eyes in the control group was (23.37±1.27) mm. The difference in axial length between the left eyes and right eyes in the control group was not significant (t=0.017, P＞0.05), while the difference in axial length between the affected eyes in the BRVO group and the right, left eyes in the control group was significant (t=−2.563, −2.663; P＜0.05). The mean anterior chamber depth of the affected eyes in the BRVO group was (2.66±0.26) mm, and that of the fellow eyes was (2.65±0.30) mm. The difference in anterior chamber depth between the affected eyes and fellow eyes in the BRVO group was not significant (t=0.089, P＞0.05). The mean anterior chamber depth of the right eyes in the control group was (2.56±0.29) mm, and that of the left eyes was (2.59±0.30) mm. The difference in anterior chamber depth between the left eyes and right eyes in the control group was not significant (t=−0.592, P＞0.05). The difference in anterior chamber depth between the affected eyes in the BRVO group and the right, left eyes in the control group was not significant (t=1.779, 1.778, P＞0.05). Conclusion In the affected eyes of BRVO, the axial length is shorter and anterior chamber depth is normal.