An adaptive controller design for a class of nonlinear single-input single-output systems with partial state constraints is presented in this paper.The approach adopted is to consider the asymmetric dead zone of the non-linear systemsand employ the barrier Lyapunov function(BLF) to prevent partial states from transgressing the constraints.Using a BLF-based backstepping technique,a good tracking performance is obtained and the non-linearity of the dead zone is addressed.For the triangular system,an adaptive controller is designed.It is shown that all the signals in the resulting closed-loop system are bounded,and the system output can track the reference signal.The simulation results show the effectiveness of the proposed method.