AIM:To evaluate the feasibility of the measure method of intraocular lens(IOL) diopter in cataract with silicon oil-filled eye by using corrected eye’s axiel. METHODS: Twenty-eight cases of silicon oil tamponaded eyes with cataract were taken in the study. Their ages were from 25 to 72. They received silicon oil extraction and cataract phacoemulsification and IOL implantation in one operation. Before the operation, they received keratometry measure and eyeball length measure at seated. During the measurement ,the speed of the supersonic wave in vitreous was corrected from 1532m/s to 990m/s. Their IOL power were calculated by SKR-Ⅱformula with corrected eyeball length. RESULTS: All the cases had silicon oil extraction and cataract phacoemulsification and IOL implantation in one operation. There were no complications. Their diopter were from -2.0D to 2.5D one month after the operation. CONCLUSION: Measurement of IOL diopter by axial length on patients with cataract and silicon oil tamponaded eyes is a feasible clinical method.