Abstract: The influence of additives on the mechanical properties of silicone rubber was studied by changing the addition of additives.The addition of silicon dioxide changed from zero to 14.5 gram per 100 gram raw rubber and the vulcanizing agent(dicumyl peroxide) changed from 0.7 to 4.5 gram per 100 gram raw rubber.The results show that the hardness of silicone rubber could be effectively improved by adding silicon dioxide;however,the addition decrease the mechanical properties due to decreases of the degree of vulcanization.The silicone rubber has good mechanical properties when the vulcanizing agent was 1.5 to 2.5 weight percent of raw rubber.