Abstract:Based on the meteorological data at 84 sounding and surface stations in China during summer half year from 1970 to 2012, the interannual variation of 0℃ isotherm height (H0) is analyzed. The result indicates that the mean H0 is between 2800 m and 5200 m in China during summer half year of the last 43 years, and the south H0 is higher than the north H0, mainly controlled by latitude and altitude. The annual mean H0 increases by 2.23 m·a-1, which has passed the 0.01 level of significance test. The change trend (p<0.05) on a monthly basis is reported for 1.82, 2.03 and 5.38 m·a-1 in June, July and September, respectively, and all have passed the 0.05 level significance test. During 1970-2012, the H0 at most sounding stations in China shows an increasing trend in summer half year. The increasing trend at northern stations is mostly over the 0.05 level, and the ascending range is generally larger than at the southern stations. The mean H0 is positively correlated to mean air temperature in summer half year with correlation coefficients between 0.07 and 0.89. The correlation coefficients for the north are higher than that for the south.