This paper is concerned with the stabilization of sampled-data-based unmanned surface vehicle (USV)rudder roll closed-loop control system.Considering the delay in the sampling process,we discuss the dynamic delay interval method and construct a corresponding Lyapunov-Krasovskii function (LKF).This method extends the fixed interval to a dynamic interval,which not only relaxes the restriction of upper and lower bounds to the delay interval but also can obtain a much less conservative delay-dependent stability criterion based on linear matrix inequality (LMI).Therefore,one can obtain a much more relaxed criterion to analyze the stability of a sampled-data-based USV rudder roll closed-loop control system.To this end,an example is given to illustrate the effectiveness of the proposed method.