Relationships of soil aggregates stability with soil loss,runoff and sediment characteristics were studied under simulated rainfall in red soils derived from Quaternary clay,Shale and Granite.Results show that soil loss and runoff rate were significantly related to aggregate stability,but the relationship varied with the aggregate stability indices.Among them,mean weight diameter with wet-sieving method and content of water stable aggregates lager than 0.25 mm were the highest in relativity.As for Le Bissonnaisπmethod,soil loss and mean runoff rate were also significantly correlated with the normalized mean weight diameter of aggregates (1～0.5 mm in size) in the fast wetting treatment and aggregates (2～1 mm in size) in the wet stirring treatment.A significant relationship (partial correlation analysis) was found between particle size of sediment and mean weight diameter (r=0.8283),water stable aggregates >0.25 mm (r=0.8209).In Le Bissonnais' method,the NMWD of aggregates (1～0.5 mm) in the fast wetting treatment and aggregates (2～1 mm) in the wet stirring treatment showed close but not significant relationship with particle size of sediments (r=0.7458,r=0.6859).However,the stream power and particle size of sediments did not show much (r=-0.1852) in this study.