In this paper, a comprehensive review on the advances of researches on physical mechanisms of ENSO cycles is given. Up to now, the results of the researches on this aspect are different because each of the researches uses different method and the discussion is focused on the different aspect of the ENSO cycle. It seems that the difference of the model dynamical process leads to the difference of the results. Finally, the GCM modelling and the prediction of the ENSO cycles are introduced.