Abstract: Laminar-turbulent transition can greatly affect the characteristics of boundary layer flow like skin friction and heat transfer.Predicting transition accurately is of great importance in engineering design.The prediction of transition using transition models which develop quickly during past years is very appropriate in engineering applications.Transition models are divided into four types and each type is reviewed in detail respectively.Conclusions are made based on a-nalysis and discussion about the achievements as well as the drawbacks of transition models now-adays,and some suggestions are proposed for transition research and modeling in the future.