Optim ization for hydrogeologic parameters in phase of model examination is the most important step ingroundwater num erical modeling． The traditional methods。such as trial—and—error method。need m uch timeand need manual intervention with experiences．It is the impassable puzzle for the people short of experience．So，many researchers study several optimization method to determining the parameters．Hooke- Jeeves methodis a kind of optimization which algorithm is simple and easy to realize． This method avoids the problem insimplex method which m ust create a series of simplex peaks first and calculate the center of simplex to find theoptim al solution． And it directly optimizes the function with trend of the value reducing．The determ ination ofhydrologic parameters problem firstly converts into a unconstrained optimization，and then unsolved with theHooke- Jeeves method．It iS a simple and practical method．