An experiment was conducted to study the seasonal dynamics of soil enzyme activities in three typical slopes(railway slope,natural slope and farmland slope)in the hilly region of central Sichuan Province.The main results are as follows:Soil enzyme activities were significantly different in the three types of slopesin every season.Soil urease and invertase activities showed specific seasonal fluctuations in the three types ofslopes.Soil urease activities peaked in April and bottomed out in January for railway slope and farmlandslope.However,for natural slope,the maximum of urease activities occurred in October and the minimumvalue,in July.Soil invertase activities were at the lowest level in January and at a relatively higher level inApril and October,for railway slope and natural slope.By contrast,soil invertase activities remained stability from January to July for farmland slope,while considerably increased in October.