Objective To observe the B-scan ultrasonic characteristics of the posterior vitreous detachment (PVD) and the relationship between the PVD and retina. Design Retrospective case series. Participants 991 cases (1107 eyes) with PVD. Methods The results of B-scan ultrasonography were retrospectively in PVD patients and according to the adhesion between the posterior vitreous cortex (PVC) and eyeball wall, complete PVD and incomplete PVD were divided. Main Outcome Measures The ratio of types and characteristics of PVD. Results 710 eyes(64.1%)were diagnosed as complete PVD, in which 69 eyes(17.3%)accompanied with peripheral ruptured detachment of retina, and 16 eyes(23.0%)PVC adhered with lid of peripheral retina hole. 397 eyes(35.9%)were diagnosed as incomplete PVD, in which 159 eyes(40.0%)as partly PVD, and 76 eyes(47.7%)concomitanted with PVC proliferation and vitreous incompletely splitting. 121 eyes(30.5%)PVC were adhered with the macula, and 117 eye(29.5%)with the optic disc. Conclusions Ultrasonography can be applied to diagnose PVD precisely,which can provide credible morphologic evidence for the clinic.