By the methods of field survey and incubation experimentations，soil microbial counts and enzyme activities on three typical railway cutting slopes located in Jiajiang section,Wufeng section，and Baiyun section of Sichuan Province were investigated. Results showed that the soil microbial counts on railway cutting slopes displayed obvious seasonal fluctuation. The quantities reached their maxima in summer on the three slopes and followed by those in spring and autumn，while the quantities reached theirminima in winter. The detailed maxima of bacteria，fungi,the average soil microbial quantity per year on the investigated railway slopes were all higher than those on natural slopes selected as controls. In addition，soil enzyme activities also presented apparent seasonal fluctuation. To be specific，the activities of all the enzymes reached their maxima in summer and autumn，as contrasted with their minima in winter. The average enzyme activities per year of the urease and the catalase on the railway slopes were all higher than those of the controls,however,the indicator of the saccharase on the railway slopes was lower than that of the controls. Seasonal fluctuadons of soil microbial quantity and enzyme activities on railway slopes were similar to that of natural slopes.Some correlations were found，including very significant correlation(r=0.999) between the bacteria and the algae inJiajiang section;significant correlation(r=0.969) between the fungi and the catalase inJiajiang secdon;significant correlation(r=0.978) between the urease and the saccharase in Wufeng section;significant correlation(r=0.963) between the bacteria and the urease in Baiyun section;and significant correlation(r=0.962) between the algea and the urease in Baiyun section. However，the correlation among all other factors on railway slopes was not significant.Temperature was the major influencing factor of soil microbial counts and enzyme. Soil microbes growth and function of micro-organism produce enzyme were disturbed by human activities.