Abstract: This paper studies the distributing characteristics and the controlling factors of ground temperature,geothermal gradient and surface geothermal current value by using the data of 28 geothermal wells in the Kaifeng geothermal field.Dividing the reservoir(depth 300~1 600 m)into 6 sub-reservoirs,the hydraulic-connection among sub-reservoir is researched also.The hydro-geological characteristics and hydrochemical characteristics of 6 sub reservoirs are assessed.The age,the circulating rate and the recharge area of geothermal groundwater are determined based on the radioactive isotope ¹⁴C content.