By statistical analysis of the data of outpatients day by day from a hospital and meteorological data in Lanzhou form 1996 to 1998, 2000, a daily grade forecast equation is built in the seasons for eight diseases, the pathological repository is also built. Based on the relation of meteorology and disease, Lanzhou medical meteorological forecasting system was built, which includes automatically collection and data processing, MICAPS system, figure display of the evolvement of the meteorological factors, edit manuscript, automatically printing system, etc. This system has already been running since October of 2001. The result shows that the forecast result has high accuracy, the system runs well and it has high robotization.