Meta-analysis used for genetic association studies became popular among researchers,with the amount of published papers increased rapidly.In this paper,we will focus on the introduction on the selection of genetic models.Traditionally,methods used for Meta-analysis on genetic association studies was to calculate the statistics based on available genetic models which not only increasing the probability of false-positives but also making the interpretation of results more difficult.Hence,a critical step in the Meta-analysis of genetic association studies was to choose the appropriate inheritance model.The aim of this paper was to introduce the theory of Bayesian analysis regarding the genetic model-free approach,in performing the Meta-analysis for studies related to genetic associations.