Polymer light-emitting diodes (PLEDs) based on fluorescent and phosphorescent electroluminescence (EL) have attracted great attention currently, and been extensively investigated. In this study, a series of copolyfluorenes (PFG1 PFG4) containing distyrylbenzene derivatives (GM) were synthesized by Suzuki coupling reaction. The electroluminescent (EL) spectra of the PFG copolymers are very different from photoluminescent (PL) spectra. The green emission (520 nm) in EL spectra are much stranger than those in PL spectra, which can be partially attributed to energy transfer from fluorene segments...