Abstract: In order to investigate the effects of epoxidation on the dispersibility of silica (SiO₂ particles) in solution-polymerized styrene butadiene rubber (SSBR) matrix, SSBR and epoxidized solution-polymerized styrene butadiene rubber (ESSBR) were used as matrix, silica were used as reinforcer firstly, SiO₂/SSBR and SiO₂/ESSBR rubber compounds and vulcanizates were prepared, respectively. Then, the structure, morphology, vulcanization characteristics, wear resistance, quasi-static mechanical properties and dynamic mechanical properties of the materials were investigated by FTIR, SEM and other testing methods. The results show that the Mooney viscosity of crude rubbers increases with the epoxidation degree growing from 0 to 14.73%. The epoxy groups in ESSBR chains react with the silanol groups on the surfaces of SiO₂ particles, thus forms stable chemical bonds which depress the aggregation of SiO₂ particles and promotes the uniform desperation of them. When the epoxidation degree is 6.87%, SiO₂ particles have the best dispersity in ESSBR. With the epoxidation degree increasing, the tensile strength of SiO₂/ESSBR vulcanizates increases firstly and then decreases, wear resistance enhances firstly and then reduces, the elongation at break decreases, stretching strengths at 100% and 300% increase, glass transition temperature increases, loss factor at 0℃ increases significantly, wet-skid resistance enhances, loss factor at 60℃ increases slightly and rolling resistance increases. Therefore, the comprehensive performances of SSBR vulcanizates after epoxidation modification enhance, when the epoxidation degree is within the scope of 6.87%-8.51%, the comprehensive performance of SiO₂/ESSBR vulcanizate reaches the best.