The parametric H_∞ control problem of nonlinear systems with uncertain parameters is investigated. Firstly, the
existence region of equilibrium involves the solution of nonlinear algebraic equations with no input disturbance. Then, when
the disturbance input exists, state feedback controllers are designed and the sufficient conditions which made the closed-loop
system parametric stable and satisfied H_∞ disturbance attenuation are formulated by using the Lyapunov function. The
simulation results show that the designed controllers can effectively stabilize the nonlinear systems and nonlinear systems
have certain H_∞ disturbance attenuation.