Abstract: The scientific assessment of the overall status of the interactions between the urbanization and the ecological environment in Chengdu is of great significance for optimizing the pace and quality of urbanization and improving the quality of the ecological environment. This study adopted the nighttime light and Landsat remote sensing data obtained from the DMSP/OLS and the NPP/VIIRS. Based on these data, the normalized night light index (NNLI) characterizing the urbanization process and the remote sensing ecological index (RSEI) characterizing the ecological quality were constructed, respectively. Then, the two indices were combined into a coupling coordination degree model for evaluation of the coordination between the urbanization process and the ecological environment quality. The study results are shown as follows. The urbanization process in Chengdu had been accelerating from 2000 to 2018, with the NNLI increasing from 0.15 in 2000 to 0.81 in 2018. By contrast, the quality of the ecological environment was negatively affected by the urbanization process and showed a downward trend in some areas, with the RSEI decreasing from 0.63 in 2000 to 0.58 in 2018. The coupling coordination degree of urbanization and ecological environment in Chengdu was gradually improved. From 2000 to 2018, the coupling coordination state entered the stage of good coordination from imbalance. However, the overall urbanization process in Chengdu is ahead of the development of the ecological environment, which is lagging behind.