The bryophytes play a very important role in soil and water conservation and water source holding in a slope ecosystem.This paper studies the species

spatial variabilit y

and the environmental factors of the bryophytes on four slopes including railway slope and natural slope along the Cheng-Kun railway and the ChengYu railway.The result shows that the species of the bryophytes are significant!Y.different between the Jiajiang site and the Jintang site.There are about 7 species in Jiajiang site

whereas only 2 species site in Jin- tang site In Jiajiang site

the species of bryophytes on railway slope are more than the species on natural slope

but the species of bryophytes in Jintang site are the same on railway slope and nat ural slope.Largest water holding of bryophytes in Jiajiang is distinctly higher than that in Jintang site.The biomass of bryo- phytes is negatively related to the weight of withered litters.However

the biomass of bryophytes is positively related to soil rigidit y

while there is a negative relation between the biomass of bryophytes and the coverage of herbage.