Abstract: Polymethylphenylsilane, poly(ptrifluoromethylphenyl)(methyl)(methylphenyl)silane and poly(ptrifluoromethylphenyl)(phenyl)(methylphenyl)silane were synthesized through the Wurtz reaction. The polysilanes were characterized by IR, GPC and fluorescence spectroscopy, and their UV degradability was investigated. The difference of the polysilanes in photoluminescence and UV degradability was explained on basis of electronic structures. Results show that the introduction of electronwithdrawing groups —CF3 at the paraposition of phenyl ring is favored to UV degradation of polysilanes. UV degradation of polysilanes is inhibited with the increasing content of phenyl rings.