Abstract: ObjectiveTo quantitatively evaluate the impact of short-term changes of daily average temperature on residents' daily mortality rate of respiratory diseases in Shenyang city.MethodsAdjusting for long-term trends of air pressure and seasonal factors,the semi-parametric generalized additive model was used to study the relationship between short-time daily average temperature and daily respiratory system disease mortality of the residents from Jan.1,1992 to Dec.31,2000 in Shengyang.ResultsA graphically significant "J" shape relationship between mortality caused by respiratory diseases and ambient temperature was found.The optimal temperature corresponding to low mortality was 22.3℃.The level and length of daily death mortality curve in low temperature(<22.3℃)was higher and longer than that of in high temperature(>22.3℃).The elderly were more sensitive to temperature changing.The mortality caused by COPD(ICD9:490.0-496.9)showed a monotone increase as the temperature decreasing.And the mortality caused by pneumonia(ICD9:480-486)was more sensitive to temperature changing at high temperature.ConclusionThe graphically relationship between ambient daily average temperature and daily respiratory system disease mortality of townsman is a significant "J" shape.