Polypropylene was blended with polydialkylsiloxane (alkyl : propyl and octyl). Some properties of the resultant polymer blends were investigated : the melt flow index at 230 degrees C, bending modulus, and Izod impact strength. Furthermore, their morphology was observed using scanning and transmission electron microscopes. It was elucidated that polydipropylsiloxane and polydioctylsiloxane, which are finely dispersed as ciliated islands in the sea of polypropylene, are effective to increase the melt flow index and Izod impact strength of the polymer blends.