Abstract: An improved map based on Logistic map is proposed. The proposed map is a novel chaos map which makes use of two levels of Logistic map. By designing fractal coefficient of Logistic map, the proposed map can effectively overcome the problems of attractor and steady window in Logistic map. Analysis and simulation of the chaotic map are carried out from the perspective of Lyapunov indicator, which show that the range of fractal coefficient of the improved map is wider than the existing Logistic map in chaotic states. Besides, analysis and simulation from the perspective of power spectrum and phase space show that the improved map has good chaos characteristic which results in excellent confidential performance in chaos hopping communications with the proposed map deployed.