Objective: To evaluate the cytotoxicity of contraceptive materials of scrotiform Intrauterine Device (IUD). Method: Make a cytotoxicity experiment with the additional liquid silicone rubber newly developed (formula: vinyl silicone oil, hydrogen silicone oil, and 1- ethynylcyclohexanol) in accordance with Part 5 of GBT16886.5-2003 Biological Evaluation of Medical Devices. 6 groups in total including blank control group (with no RPMI1640 complete culture solution of the experimental material), negative control extract solution group (high Density Polyethylene material), positive control solution group (with RPMI1640 complete solution of 6.3% phenol), 100%, 50% and 25% material extract group were set. Cultivate L-929 cell with RPMI 1640 complete culture medium ; add 100 μL blank control solution, negative extract solution and 25%, 50% and 100% material extract solutions, and observe cellular morphology under the microscope; and measure OD value with a microplate reader and observe proliferation rate of the cells. Results: Blank control group, negative control extract solution group, positive control solution group, 100% ,50%,25% material extract group’s cell cytotoxicity of experimental materials are in level 0, 1, 4, 2, 2 and 1 respectively . After 72 hours, 25% ，50% and