Abstract: A new robust stability criterion for uncertain systems with multiple state-delays and nonlinear time-varying perturbations is obtained by the matrix inequality technique．In these systems‚the delays are unknown constant‚the time-varying parameter uncertainties are norm-bounded and the nonlinear perturbations meet certain linear constraints．Then‚on the basis of matrix inequality technique and Lyapunov functional‚a delay-dependent robust stability criterion expressed as LMI （Linear Matrix Inequality） is established．It is finally shown by two examples that‚compared with the methods presented in the literatures‚the method presented in this paper can reduce the conservativeness of the results‚which indicates the validity of the proposed method.

Key words:  nonlinear perturbation, uncertain time-delay, delay-dependence, stability