The effect of urease inhibitor quinhydrone(HQ)on kinetic parameters of urease in three typical soils(iealbic soil,brown soil,cinnamon soil)in Northeast China under different temperature conditions.The results showed that,soil type,incubation time,incubation temperature and their interactions significantly influenced soil urease kinetics.Compared with control,Km increase and Vmax decrease in the soils with HQ and it showed HQ was mixed inhibition to soil urease.Compared with albic soil,in brown soil and cinnamon soil the influence on kinetic parameters of soil urease as affected by HQ was greater,which indicated that high fertility soils could have stable biological characteristics.With incubation time increasing,Km decreased,but Vmax and Vmax/Km increased.With incubation temperature increasing,Km and Vmax increased,Vmax/Km changed irregularly.Statistical analysis indicated that,Km,Vmax and Vmax/Km of soil urease had significantly correlations with pH,organic matter,total nitrogen,alkalihydrolyzed nitrogen and texture structure.