We report on the emission characteristics of the polymeric light-emitting diodes (PLEDs) with the blend of a copolymer containing MEH-PPV and SiPh-PPV unit (m-SiPh PPV-co-MEH PPV) and a polyvinylcarbazole (PVK). According to change of their blending ratio, the PLEDs showed the change of electroluminescence(EL) intensity and EL spectrum. The EL characteristics were improved when the PVK was a small quantity. Most effective PLEDs with m-SiPh PPV-co-MEH PPV copolymer-rich blend for EL enhancement was when the blending ratio of m-SiPh PPV-co-MEH PPV: PVK equals to 70:30 by weight ratio. It is thought as the result of the m-SiPh PPV-co-MEH PPV's dilution effect and the role of the PVK with hole transport ability. On the other hand, we have attempted to tune the EL color of the m-SiPh PPV-co-MEH PPV EL cells by the blending with the PVK. According to increasing of PVK content, the emission peaks of the PLEDs have blue-shifted from red light. White emission which covers the full range of the visible region is realized when the weight ratio of m-SiPh PPV-co-MEH PPV:PVK equals to 4:96, which shows the CIE coordinates are x=0.3266 and y=0.3438.