In this work, the adaptive control scheme for a class of input-output linearizable nonlinear systems subjected to system uncertainties is presented. An adaptation law is proposed to estimate unknown system parameters such that the effect of the system parameter uncertainties can be reduced and a switching state feedback gain is set in the adaptive control input to treat with unmodelled dynamical uncertainty problems. Then a robust adaptive control scheme in the presence of the above system uncertainties can be ensured. It is further indicated that the proposed adaptive control scheme will be robust asymptotically stable under some modifications. Some computer simulation results are proposed to show the performance of the proposed adaptive control scheme.