Abstract: [Objective][Method] Different kinds of underlying surfaces of urban green in Beijing are selected to study their air temperature, relative humidity and human body comfort index by using small-scale quantitative measurement method. [Result]The result shows : 1)The type of underlying surfaces have a significant correlation with air temperature and relative humidity, the characteristics of the other sixteen plots have no significant correlation with air temperature and relative humidity. 2)The order of average temperature-humidity effect for different underlying surfaces daily in summer is Tree-shrub-herbage> Tree-herbage > Shrub-herbage > Lawn Bare > Land > Cement pavement. 3)8:00～18:00,except 18:00, the order of the temperature-humidity effect for different underlying surfaces in each period is consistent with the effect of daily average; The effects of temperature-humidity (include negative effect) for the underlying surfaces reach the maximum at 14:00, Tree-shrub-herbage can decrease the air temperature with an average of 4.50 ℃ and increase the relative humidity by 7.45 %, Cement pavement can increase the air temperature with an average of 2.03 ℃ and decrease the relative humidity by 2.82 %. 4)The order of human comfort index for different underlying surface is nearly Tree shrub herbage> Tree herbage > shrub herbage> Lawn Bare> land> Cement pavement.