Abstract: Based on the 45 seismic sequences collected in Chinese mainland, the maximum likelihood estimation method is used to calculate the variation coefficient of earthquake sequences with different sample size, and the correlativities with the parameters of the corresponding fault source are carried out, and then the estimated values are standardized. Finally, a general value α_c=0.37 of aperiodicity is given. The results of the correlation analysis show that the variation coefficient is negatively correlated with the length of the fault and the horizontal slip rate, so the application of the general aperiodicity value （α_c=0.37） is analyzed. The result show that the three α values （0.21, 0.37, 0.53） obtained by performing standard deviation operation to α_c are applied to the active faults with significantly differences in characteristics.