The problem of quadratic stability for a class of uncertain nonlinear systems using Takagi-Sugeno fuzzy model is solved and certain relaxed conditions are derived. Firstly, a new robust quadratic stability condition via designing state feedback controller for T-S fuzzy system with uncertainties is derived. This condition is represented in the form of LMI and it is shown to be less conservative than similar known relaxed quadratic stabilization conditions in recent literature. Secondly, a dynamic output feedback control design for complex nonlinear systems represented by T-S fuzzy model is derived. These new techniques consider the interactions among all fuzzy subsystems. Finally, the applicability and validity of the proposed approach are demonstrated by means control design and simulation results for an illustrative example.