Finding canonical metric is one of the important problems of geometry. Mabuchi functional is a functional on the space of Kähler potential defined by Toshiki Mabuchi in 1985 which can be used to find the constant scalar curvature Kähler(cscK) metrics on the given Kähler class. In this talk we will prove a modified form of Mabuchi functional by Xiuxiong Chen and get a sufficient condition for the existence of cscK metric.