This　paper　proposed　a　novel　trajectory　tracking　control　method　for　the　wheeled　mobile　robot　with　unknown　skidding,　slipping　and　uncertainty　of　dynamics　system.　The　method　is　based　on　sliding　mode　control　and　disturbance　observer　by　using　back-stepping　design　technology.　The　WMR　system　uncertainties　of　parameters　and　non-parameters　are　compensated　fast　through　disturbance　observer.　In　combination　with　sliding　mode　control,　the　compensating　error　is　eliminated　further,　such　that　the　control　precision　is　improved,　the　chattering　of　sliding　mode　control　has　also　been　eliminated.　During　the　design　process,　the　technique　of　Lyapunov　is　used,　which　has　proved　that　the　control　system　is　asymptotically　stable,　and　the　simulation　results　verify　the　effectiveness　of　the　methods.