The rapid survey and assessment study on region-scaled soil and water loss is very sigificant macro-decision-making of regional soil loss control,quick control to natural disasters and construction poster-regime on soil loss regularly.Based and on the study of region-scaled soil loss and 3S application,the rapid assessing method is put forward and taking the whole loess plateau of China as a sample region,series of indices are defined; the model is set up to help to appraise the soil loss in this region; finally，soil loss of the loess plateau is assessed using the model,and some fine results have been got.