A series of the electronic structure and properties of non-conjugated polymer host molecules by incorporate the suitable substituents into the 4,4-Vinyltriphenylamine(STPA)[1] for green electroluminescence are calculation by density function theory(DFT).The results show that the substituent effects and position has a great influence on the properties of polymers,N atom linked para-carbazole,β-pyrrole and triphenylamine are favorable the hole injection,and linked para-carbazole could increase the triplet energy(ET)of the host molecules.The structure between the lowest triplet state and ground state change large make a lower ET,and the lowest triplet state structure plays a decisive role.The energy different between the lowest singlet and triplet excited energy of host molecules,which determines all the designed molecules with a lower device turn-on voltage.We also consider that the efficient energy transfer mechanism of S1→S1 and T1→T1 between host and guest,we found all the host materials are suitable with green light.We constructed a simplified model to study the charge transfer between host and guest molecule,the results show that host and guest molecules with a good interaction.In the designed host molecules,N atom linked para-carbazole substituted the STPA,show a great potential for the green phosphorescent polymer light-emitting diodes [2].