Abstract: The Bayesian method is introduced into the field of groundwater to identify hydrogeological parameters,which is usually a complicated nonlinear problem.A Bayesian hydrogeological parameter identification algorithm is proposed based on the MCMC sampler which is coupled with the groundwater modeling software,Modflow.The efficiency of identifying high dimensional parameters is greatly improved by using the SCAM sampler and a weighting factor.Two examples are presented to illustrate the distinctive optimization performance of this algorithm.The results indicate that the proposed algorithm is capable for complex groundwater problem and shows outstanding advantage of global optimization.