The purpose of the experiment is to research the effect of different rapeseed treatments feeding on activity of cellulose enzyme in sheep. Eight male adults of semi-fine wool sheep breeds with the same weight and permanent rumen cannulas were selected according to 4×4 Latin square design to determine the effect of different rapeseed treatment groups including crushed rapeseed, whole rapeseed, extruded rapeseed (dietary lipid content of =67 g·kg-1) and control group (dietary lipid content of =30 g·kg-1) on activity dynamic variation of ruminal celluolytic enzyme in sheep. The results showed that ruminal fluid pH matched up to the condition of fiber degradation and growth of cellulolytic bacterium when fed four diets; but there was significant difference (P<0.05) for the activity of microcrystalline cellulose, glucanase, salicin enzyme involved in ruminal fiber degradation after fed 2,4,6 h.