The 5-day average of the 500hPa height field as predictors and the pentad regional precipitation of 4 areas in sanxia,China as predictands were used to build the BP Canonical Correlation Analysis(BP-CCA)model.The forecast skills of BP-CCA for the precipitation of 4 areas were estimated by using a cross-validation technique.The forecast test shows that the predictive skills of BP-CCA for areal precipitation forecast in sanxia areas are good enough for the operational medium range weather forecast and the results are valuable for reference to forecasters.