Abstract: Considering the narrow range and low sensitivity of recent chromatic dispersion (CD) monitoring by the asynchronous amplitude histogram (AAH) method, a novel CD monitoring technique based on asynchronous amplitude sampling(AAS) for higher order modulation formats was proposed. The parameter G, which can separate the CD from the other impairments effectively was defined. The monitoring system for 200 Gbps DP-16QAM was constructed by simulation software OptiSystem9.0. Under different optical signal-to-noise ratio and duty cycles, the dispersion monitoring was realized. The deviations caused by OSNR and varied duty cycles were investigated, and the inaccuracy was analyzed. Simulation results show that the method based on parameter G possesses the advantages of lower influence of noise and higher precision, which leads to effective monitoring of the dispersion within 0-600 ps/nm. And this method can provide a reference for the monitoring and management of dispersion in optical fiber communication system with higher order modulation signals.