There was a very good observation area in Chongqing for the total solar eclipse along the Changjiang river on 22 July, 2009.Through the experiments, the outdoor meteorological data (solar radiation, air temperature and relative humidity) were observed and recorded on 21 July and 22 July.Based on the experimental observation data, the effect of thermal environment in Chongqing area was to analyzed and discussed.Experiment indicates that the reduction of air temperature and surface temperature resulted in the decrease in the solar radiation intensity, and the amplitude of the air temperature change is 2.4 ℃ during the total solar eclipse.Compared with the two days’ air temperature, the amplitude of the air temperature change reached 4.6 ℃ on account of the total solar eclipse.