Abstract: Heat island effect is one of the most striking impacts of urbanization on eco-environment. It is important for the construction of new cities to evaluate the temporal and spatial change of heat island effect during the process of urbanization. Chengdu-Chongqing urban agglomeration is located in the western part of China, consisting of 2 megalopolis and 14 large, medium, and smallsized cities. The heat island effect is increasingly outstanding in recent years due to the development of urbanization in these areas. In this study, based on the MODIS/Terra monthly land surface temperature (LST) data from 2000 to 2010, we analyzed the heat island effect of Chengdu-Chongqing urban agglomeration by calculating the difference of average temperature between urban and rural areas of the 16 cities. The results showed that: (1) The seasonal and diurnal heat island effect in Chengdu-Chongqing urban agglomeration was relatively obvious. (2) The heat island intensity in mega-cities Chengdu and Chongqing was greater than in the other 14 cities, and a significant correlation was observed between the built-up area and the daytime heat island intensity. (3) The overall heat island intensity decreased by 0.3 ℃ during 2000 and 2010. In the meantime, the heat island intensity in old towns increased by 0.21 ℃, and the change was slight in the daytime and significant in the nighttime.

Key words: clone, exponential fertilization, chlorophyll fluorescence