A method of improving the traditional Hénon map is proposed in the paper. The internal structure of the system is changed by adopting absolute value term. The linear complexity and sensitivity to initial conditions of the proposed system have been greatly enhanced. The performance of pseudorandom-bit sequences which are generated by the proposed system is analyzed in comparison with the ones that are generated by chaotic system. The performance of the sequence generated by the proposed system is improved compared with the original system. Theoretical analysis and the simulation results show the feasibility of the method.