Abstract: For the robustness of networked control system(NCS),a predictive control method based on online least squares support vector machine(LS-SVM) is proposed.Based on LS-SVM,training data window and training data threshold are employed to develop an online training method suitable for the control system.When the kernel function is linear in the online LS-SVM,the control variable can be solved by integrating the method of predictive control.In order to make validation,the method is applied to the NCS which has time delay,data packet dropout and desequencing.The results of simulation show that the presented method is rapid,accurate and robust.