The observation of thermotropic cholestric liquid crystal in helical polysilane is presented. The molecular weight has significant effects on the thermotropic phase behavior of the polysilanes. It has been also found that the transition temperature is gradually increased with the increase in the molecular weight. Iridescent colors due to light reflection from randomly aligned textures suggests that lack of positional order assosiated with the presence of chirality, the liquid crystal of polysilane should be a cholesteric phase.