AIM: To evaluate application value of high-frequency color doppler flow imaging (CDFI) on the pre-operative diagnosis of vitreous hemorrhage. METHODS:High-frequency CDFI was performed on 20 patients (20 eyes) with vitreous hemorrhage(VH). Pre-operative diagnosis was given by CDFI, fundus examination and previous history. All patients were performed vitrectomy. Post-operative diagnosis was based on observation during operation, post-operative fluorenscense angiography and indocaine angiography.  RESULTS:In these 20 eyes with VH, there were 5 eyes (25%) with retinal detachment, 2 eyes (10% ) with retinal detachment and choroidal detachment, and 2 eyes (10%) with subretinal hemorrhage. It was evidenced by operation that there were 7 cases (35%) with proliferative diabetic retinopathy, 7 cases (35%) with central or branch retinal vein occlussion, 3 cases (15%) with rhegmatogenous retinal detachment, 1 cases (5%) with age-related macular degeneration, 1 case (5%) with polypoid chorioretinopathy, and 1 case (5%) with Eales disease. The CDFI results of 19 eyes among 20 eyes (95%) were consistent with the observation in surgical operation.  CONCLUSION:High-frequency CDFI can contribute to preoperative judgment for the cause of VH, and to effectively guide clinical treatment.