Abstract: Using monthly data of NCEP/CAR and rainfall of China,the North China rainfall relationships with the circulation anomalies and the heat source over the Asian monsoon area were investigated. The results indicate that the Asian summer monsoon is weaker in drought years of North China,but stronger in flood years of North China. There are two centers of change,one over middle and north India Peninsula,and the other near the Phillipines. There are also obvious changes of corresponding heat source over the Asian monsoon area. Over the two areas,the heat sources are weaker in drought years, but stronger in flood years of North China. There have been obvious differences of heat source in earlier months in drought years or more rainfall years over North China. In drought years,the heat source and the moisture sink are weaker and located to south, showing a delay seasonal change. In more rainfall years, they are stronger and located to north,showing a preceding seasonal change. By using the IAP L9R15 ALCM model,the influences of latent heat anomalies are further examined. It is explored that the latent heat anomalies over the middle and north India Peninsula and Phillipines influence the rainfall of North China through the West Pacific subtropical high and Tibetan high.