This paper presents a numerical modeling method for monthly-scale regional climate prediction for East China. The main dynamic framework of the forecast system is composed of an improved coarse-resolution general circulation model (GCM), i.e., T63L9, and a nested fine-resolution regional climate model, i.e., RegCM3, into which the hydrological model VXM is incorporated. The forecast is made from the integration results of the nested models with systematic errors being eliminated to some extent. The results of the temperature and precipitation for 2003 and 2004 are evaluated following the evaluation methods by National Climate Center. In addition, the results of the forecast system are compared with CMAP reanalysis data ，NMC temperature reanalysis data and the data of 160 stations in China. All these results show that the system can forecast stably the precipitation and the temperature for East China on monthly scale, and the system can be applied for climate operational application.