By contrasting the data of Anding Hospital's 5000 psychosis in Tianjin in 1997～ 1999 and meteorological data，the relationship between the meteorological factor s and invasion rate was discussed.The variation r ules of invasion and meteorological factors was revealed. The highly correlative factors were chosen and the forecasting model was established by multiple regression analysi s. A better predictive effect has been found. It will have importance in being u sed in operation.