A micro environment monitoring system has been developed to quantify the impact of micro environmental parameters on color decay of color paintings’ at Chinese classical garden. The environment parameters including temperature, humidity, velocity and sunlight in micro environment is a were recorded for the whole year at the Summer Palace. Besides, the color parameters of color painting were recorded periodically. Then fit curve graphs were obtained with dominant wavelength, excitation purity and luminance changed over time. Comparative analysis of micro environmental test data and color decay curve revealed that the temperature, humidity and wind speed has slight impact on the color of color painting, while sunlight is the dominant factor responsible for the color decay of painting. The extents to which the sunlight affect dominant wavelength, excitation purity and luminancewere different.are different on and impact of sunlight on different colors are different.