CUACE (CMA Unified Atmospheric Chemistry Environmental Forecasting System) is a unified chemical weather numerical forecasting system with BC, OC, Sulfate, Nitrate, Ammonia, Dust and Sea-Salt aerosols and their sources, gas to particle processes, SOA, microphysics and transformation. It has been designed with open interface to make it easily being coupled to different time and spatial scale models. It has been online coupled to mseoscale model MM5 and in the near future it will be coupled onto a new NWP forecasting GRAPES, Global/Regional Assimilation and Prediction Enhanced System.