Abstract: Based on analyzing the chemical composition, isotope, terrestrial heat and geological condition, this paper studied supply sources of ground hot water in this area. The δD is -65 ‰ to -80.67 ‰ and the δ18O is -9.2 ‰ to -10.2 ‰, both are located in the vicinity of the global rainfall line indicating the main cause of ground water in the area is atmospheric precipitation. Northern Ji'nan geothermal field ground hot water supply elevation is 256m, which is roughly equivalent to the mountains south of Ji'nan and the northern foot of Taishan mountain; while geothermal field ground hot water supply elevation in the east of Liaocheng is 411m, which is roughly equivalent to Taishan mountain and its surrounding mountains. Excess parameter of deuterium(d) of geothermal field ground hot water in the east of Liaocheng was significantly lower than that of geothermal field in the north of Ji'nan. It indicates that geothermal field ground hot water supply area in the east of Liaocheng is farther than the latter one.