The optical properties of porous silicon (PS) and poly[2-methoxy-5(2′-ethylhexyloxy-p-phenylenevinylene)] (MEH-PPV) polymer composites were investigated. The experiment results showed that the luminescence intensity of the composites was enhanced and the PL peak position was found red shift. The pore structure of PS decreased the collision and increased conjugation of MEH-PPV molecules, which caused the enhanced luminescence of the composites. Also, the reaction between the surface states of PS and MEH-PPV molecules provided a route of non-radiation recombination that then transferred a part of excitation energy of PS to MEH-PPV. And the excitation transfer caused the enhanced luminescence and red shift.