Temperature and shear rate dependence of appearances in extruded silica filled styrene butadiene rubber compound have been investigated by capillary rheometer. It was revealed that flow instability spiraling or melt fracture phenomenon took place with increasing shear rate. The shear viscosity with Bagley correction and the extensional viscosity calculated by Cogswell’s method were also investigated to look into reveal the relationship between extrudates’ appearances and their flowing properties. The shear viscosity with Bagley correction didn’t respond to the flow instability occurrence. The extensional viscosity calculated by Cogswell’s method, however, responded to increasing extensional rate and then, melt fracture was observed. This phenomenon indicates that melt fracture occurrence for silica filled elastomer is due to strain-hardening by extensional flow in entrance of capillary die.