Abstract： Based on simple genetic algorithm(SGA)，an improved genetic algorithm (IGA) is put forward. The decimal system is used to overcome the shortage of binary system in function optimization problems. The operating method of younger generation chromosome prepotency(YGCP) is put forward. The best chromosome clone(BCC) operation and multi-generations adjusting environment(MGAE) operation are used. The algorithm is of several main functions，such as expediting constringency，avoiding earliness，and improving precision，when it is used in parameter identification of groundwater flow model. 3D unsteady state flows in inhomogeneous，isotropic confined aquifer are taken as an ideal model，and the application process of the algorithm is discussed to inverse problem of hydrogeology parameters with finite element method. It is shown from calculation results that the presented algorithm is very effective，and is of vast application vista for groundwater seepage flow and groundwater resource evaluation.
