Abstract:This paper studied on influencing factors of soil biological crust degradation in Hilly-gullied Region of Loess Plateau.Based on investigation of vegetation,litters and biological crust,the factors of vegetation and litters as well as biological crust's growths status that related to biological crust degradation was analyzed.The results indicated that: 1) The change of vegetation coverage and basal coverage has great influence on the degradation of biological crust,but it has no significant influence on coverage and degraded degree of biological crust degradation underside of the litters.Those showed that biological crust degradation in the interspaces of plants was rarely influenced by living higher plants.2) The process of biological crust degradation no related to its growth status,it was affected mainly by other factors.3) Coverage and thickness of litters was important influencing factors to biological crust degradation underside of the litters,and it was also important influencing factors to degradation coverage of biological crust.