Different blends of SBR/NBR compatibilized by butadiene rubber (BR) were prepared according to the well-known standard methods. The modified blends of unfilled SBR/NBR was characterized on the basis of the effect of blend ratio by curing parameters, mechanical characteristics, abrasion resistance, compression set and swelling properties. It was found that SBR/NBR blends showed comparatively better mechanical properties compared to each rubber individually. Curing parameters e.g. low torque (ML) and high one (MH) were increased, while a reduction in the curing and scorch times were decreased with increasing SBR ratio in the blend. Results revealed that, the increase of SBR content results in an enhancement of tensile strength (TS) and elongation at break (Eb). The effect of blend ratio showed a peak value for (TS) & (Eb) at 50SBR/50NBR. For that, two types of carbon blacks, N220 and N774 were incorporated with the optimum blend ratio (50SBR/50NBR) by different concentrations. The effect of carbon blacks on the mechanical characteristics, hardness, abrasion resistance, compression test and even the swelling test in benzene have been discussed according to the recent current theories.