According to sounding data measured at Tuotuohe station in the central Tibetan Plateau during 1977-2010, the trend of 0°C atmospheric height in the headwaters of Changjiang River was analyzed as well as the relationship with surface air temperature in summer. The study results show that the mean height during 1977-2010 is 5536 m in the study region, the mean height in June is slightly lower than that in July and August, and the mean surface air temperature in June is also smaller than that in July and August. The trend magnitudes of 08:00(Beijing time, hereafter the same), 20:00 and their average are 16.5 m per decade, 4.2 m per decade and 11.4 m per decade, respectively, indicating that the colder time has experienced a more warming trend and the surface air temperature also shows similar monthly distribution. In July, the height shows an increasing trend by 35.6 m per decade, and the trend magnitudes of heights in June and August are 0.3 m per decade and 2.5 m per decade, respectively. Surface air temperature correlates with the height positively, and the correlation coefficient between the surface air temperature and height is 0.782, which has passed the statistically significant level at 0.01.