Early Cenozoic is the last green-house climate in geological history. With development of Antarctic ice-sheet, the Earth entered a glacial period of Late Cenozoic Ice Age. The causes of green-house climate and the transition to ice age have become an important issue in international paleoclimate modeling community. This paper reviews a series of Early Cenozoic climate simulations, discusses the climate model's developing, the boundary conditions and the experiment designs, and analyzes the impacts and feedbacks of atmospheric green-house gas, topography, oceans and terrestrial ecosystem on Early Cenozoic climate system. These modelingsfocused on the major factors of Early Cenozoic climate changes and tested the inner and external forcing in the Earth climate system, which provided us an understanding of the mechanisms in warm climate change and an important scientific basis for predicting the future climate changes.