Abstract: The combinatory forcasting method of regression-markov chain can be easily used to correctly predict groundwater regime in the grounewater system with tendency and random characteristics.The tendency part of them can be calculated in functional equation that is gotten by regression and discribes tendency variation ot the system.The random part can be forecasted with Markovian process,which is done by transfer probability.The principle of this method is simply introduced in this paper,and one example is also given.