Taking the urban green space (UGS) in the main urban area of Fuzhou as the research object, the relationship between the UGS evolution and the change of land surface thermal environment was obtained based on the remote sensing inversion of land surface temperature (LST) and the extraction of land use and land cover (LULC). The results showed that: (1) From 1993 to 2016, the area of UGS Loss and UGS Expansion were 46.50km² and 4.73km² respectively, with the area difference as high as 41.77km². The land surface temperature difference (ΔLST) caused by the UGS Loss was the largest, while the ΔLST caused by the other three evolution types was slightly lower than the average ΔLST. (2) There was a trend that the urban cold island (UCI) decreased sharply and an opposite trend of the urban heat island (UHI) in 23 years. The distribution of the LULC in temperature grades was obviously different. The low temperature zone was distributed with more wetlands and waters. The sub-low temperature zone was given priority to forest/grass, while the UHI area was more distributed with the construction land and bare land. (3) The space gravity method illuminated that there was a close relationship between the UHI and the urban center of gravity, which was negative correlation with UGS location. The UCI was the contrary in the case. (4) The cooling effect caused by different types of UGS evolution was quantified which was in order as: UGS Expansion > UGS Unchanged > UGS Exchanged > UGS Loss. The calculation showed that the average cooling effect of UGS Expansion was about 5.0 ℃, while the warming effect of UGS Loss was about 7.0 ℃. Increasing the same area of UGS cannot offset the warming effect caused by the UGS loss previously during different evolution process. Therefore, the scientific and rational UGS planning is very important to relieve UHI effect.