In order to know frequency of choroidal circulatory disturbance, 126 eyes with central serouse chorioretinopathy followed-up between Jan. 1985 and Dec. 1990 were retrospectively investigated by fundus fluorescein angiography. Appearance of choroidal circulatory disturbance was divided into two types. The type 1 showed choroidal filling delay at late retinal venous phase. The type 2 showed mosaic pattern of choroidal background at late retinal venous phase. Among the 126 eyes, 3 eyes were type 1 (2.4%) and 57 eyes were type 2 (45.2%), totaling 60 eyes (47.6%). Sixty-three eyes with normal part of branch retinal vein occlusion matching in sex and age were selected as controls. In the controls, no eye was type 1 (0%) and 8 eyes were type 2 (12.7%), totaling 8 eyes (12.7%). Distinctly, proportion of the type 2 was higher in central serous chorioretinopathy than in branch retinal vein occlusion. In conclusion, the pathogenesis of central serous chorioretinopathy is related to choroidal circulatory disturbance and especially mosaic pattern (type 2) was found to be a new type of circulatory disturbance.