Thermogravimetric analysis (TGA), flammability and oil resistance in natural rubber (NR) and dichlorocarbene modified styrene butadiene rubber (DCSBR) blends were investigated as a function of different composition. TGA plot confirms the better thermal stability and flame resistance of DCSBR as well as its blends with NR. The simultaneous difference temperature plot showed the energy requirement for the degradation pattern of the blends. The flammability of the blend was monitored by the limiting oxygen index (LOI) measurement of the rubber vulcanizate. The amount of DCSBR in the blend significantly affected the properties of blends. The mechanical properties investigated after the immersion in ASTM oil was tensile strength, modulus, tear strength and hardness. It was found that these properties were decreases progressively with increasing NR content in the blends. (C) 2004 Elsevier B.V. All rights reserved.