Clostridium paraputrificum M-21 was transformed with several shuttle plasmids constructed for Clostridium acetobutylicum-Escherichia coli and Clostridium perfringens-E. coli by electroporation. The Clostridium stercorarium xylanase gene xyn10B was successfully expressed in C paraputrificum M-21 and the expressed protein did not suffer from proteolysis by host protease(s). This system will provide us with a genetic tool for genetic and metabolic engineering of this bacterium.