Trichoderma T21 and its four REMI transformants were studied.Their antagonistic ability against Botrytis cinerea,biocontrol efficiency in greenhouse and three extracellular enzymes(chitinase,β-1,3-glucanase and cellulose) were examined.The results showed that five Trichoderma strains had different inhibitory effect to Botrytis cinerea,and Ttrm68 was the best.Biocontrol efficiency of Ttrm68 was the best too.The activity of chitinase and β-1,3-glucanase of Trichoderma with better inhibitory effect were higher,nor was the activity of cellulose.