The chaos tracking control problem is studied for a class of uncertain time-delay chaotic systems. Based on the principle of sliding mode control (SMC), a novel adaptive design scheme is proposed. The approach not only overcomes the drawback reported in the literature, but also removes the assumptions that the dead-zone is symmetric and the slopes are known. By theoretical analysis, it is shown that tracking error asymptotically converges to zero. Finally, simulation results of Duffing-Holmes chaotic system demonstrate the effectiveness of the proposed approach.