In this paper,main compositions of 8 hydrochemical ovservation items in Xiaguan hot spring in 1992 have been analysed and the disturbance factors have also been studied.The results show that radon and air pressure,water temperature and PH values,argon and nitrogen,and CO₂ are 4 main compositions which have stronger independence.Air pressure and flow quantity are the main disturbance factors to the chemical compositions.