FENG Yu-lan's philosophical thoughts are analysed comprehensively in this thesis. The paper tries to redefine the contents of new Confucian school of idealist philosophy of the Song and Ming Dynasties, and give some new demonstration to his philosophy system. Then The paper presents a brief introduction of Liao Ping's thoughts, which in fact indicates the end of Jing Xue Age in FENG Yu-Lan's view. This paper reminds readers of the differences of his ideas in A History of Chinese Philosophy. Meanwhile the paper tentatively examines his controversial thoughts after 1949 and the reasons for that.