Ground water in Sanshandao mine field consists of sea water, Quaternary water, fissure water in base rock, underground hot water and fresh water. To maintain normal production,water quality must be analysed, but the conventional simple analytic method only distinguishes water type and fails to provide other relevant data. Therefore, isotope analytic method is used, which not only verifys hydro-geological investigation results, but also provides data missed in that investigation. Such as relative retention time of ground water, make-up rate and ratio of ground water of different genesis and composition.