Abstract: To investigate the fracture behavior of silicon rubber,tensile tests at different loading rates of 10,100,200 and 500 mm·min-1 were conducted,and the fracture surface of tensile test pieces were observed by scanning electron microscopey (SEM).The tensile strength of silicon rubber increase and the tensile elongation at break decrease with the increases of loading rate.The property dispersivity decrease.When the loading rates are relatively low,the origination regions are smooth and exhibited mirror fracture characteristics.When the loading rate reache 500 mm·min-1,the fracture characteristic of origination region varied and the second cracks are obviously observed.The propagation regions of cracks become coarser with the increase of loading rate.The causes of the fracture characteristics are analyzed and analogical analysis was carried out with practical components.