Abstract: The labile organic matter and enzyme activities of urease,invertase,catalase and dehydrogenase were studied in soils treated with no organic fertilizer(CK),with waste culture material of Pleurotus ostreatus(T1),dried composted cattle dung(T2) and dried chicken manure(T3) during the growing period of cucumber(0-150d).The results showed that different fertilizers had different effects on the contents of total organic matter,following the order from high to low: dried chicken manure,waste culture material of Pleurotus ostreatus,dried composted cattle dung and control.For the effects on the contents of labile organic matter,the order was waste culture material of Pleurotus ostreatus dried chicken manure dried composted cattle dung control.Enzyme activities of urease,invertase,and dehydrogenase in soil treated with waste culture material of Pleurotus ostreatus were the highest,and the enzyme activity of catalase was highest in soil treated with dried composted cattle dung.Labile organic matter showed significant positive correlations with the activities of urease,invertase, and dehydrogenase.It was concluded that the content of labile organic matter and soil enzyme activities could be improved efficiently when waste culture material of Pleurotus ostreatus was used as organic fertilizer.