This paper is concerned with a fuzzy robust $H_\infty$ control problem via output feedback for a class of uncertain nonlinear systems. The uncertain nonlinear systems are represented by fuzzy Takagi-Sugeno (T-S) model, and a fuzzy controller is designed based on the state observer. A sufficient condition for the existence of fuzzy controller is given in terms of the linear matrix inequalities (LMIs) and the adaptive law. Based on Lyapunov stability theorem, the proposed fuzzy control scheme such that the desired H∞ performance is achieved in the sense that all the closed-loop signals are uniformly ultimately bounded (UUB). Simulation results indicate the effectiveness of the developed control scheme. In this paper, a less conservative fuzzy tracking controller is proposed, where the matching condition and the upper bound are avoided. Comparing with the existing works, the dimension of the LMIs of this paper is reduced.