Based on vegetated-slopes and outdoor simulated rainfall events,the different influence of vegetation,rainfall,underlying surface condition on the total runoff amount and total sediment yield for one rainfall event was investigated by path analysis and grey relational analysis.Results indicated that the results of path analysis are in agreement with that of grey relational analysis.The rainfall intensity,vegetation coverage and antecedent soil moisture are the three most important factors that influence the total runoff amount,and followed by vegetation types,rainfall duration,vegetation growth stages and slope gradient.The vegetation coverage and rainfall intensity are the two important factors that influence the total sediment yield,and rainfall duration is the least significant factor.