Abstract: This article discusses the difference between two Bayesian models. With model 1, it is assumed that xi（i=1,2）is conditional independent under θi（i=1,2）. While with model 2, it is assumed that xi（i=1,2）is unconditional independent. The question is that when working for the Bayesian estimation of θ1, is there any difference on the results under the two different models? The numerical comparison shows that there is only small difference between the results. So the simpler model 2 can replace the model 1, when Bayesian estimation of θ1 is calculated.