The system for numerical ultraviolet (UV) prediction (GRAPESUV) using Goddard shortwave radiative scheme with GRAPES (Global/Regional Assimilation PrEdiction System） is established. The Goddard shortwave radiative parameterization scheme and the executing of the GRAPESUV system are described, and case studies are conducted. It is shown that the effect of cloud microphysical processes in GRAPES on UV forecasts is important; the improvement of the cloud microphysical scheme make UV forecasts based on weather possibly; ultraviolet index （UVI） correlates to cloud distribution and weather situation; the strong contrast of UVI between clear sky and convective cloudy areas is an important feature of UVI. An application experiment of total ozone prediction was conducted using T213 to provide the meteorological background for the chemical transport model and using the satellite data assimilation technology to establish the initial fields. The UVI forecasts for Beijing and Shanghai in the summer of 2007 are verified statistically using the Critical Success Index (CSI) in common use internationally. The CSIs corresponding to the high and very high exposures of UV grades in 24 hours for Beijing and Shanghai are 0.625 and 0.780 respectively, approaching to the results of verification for United States with the same method. The GRAPESUV system has been running on the operational IBM computer system at the Center for Atmosphere Watch and Services (CAWAS), the Chinese Meteorological Administration (CMA), since March 2006, and has issued forecasts for UVI and UV exposure grades to remind the public of overexposure to UV radiation at the CMA/CAWAS website.