Abstract: The time series data of over M5.0 earthquakes since 1484 in Capital area are analyzed with maximum entropy spectrum analysis and maximum entropy principle method.The results show that there is a 12.9 years predominant cycle in the series.The probability for 5.0≤Ms6.0 and 6.0≤Ms7.0 earthquake in the next 50 years is 0.9907 and 0.6916 respectively.The probability for 7.0≤Ms8.0 earthquake is relatively lower, just 0.2564.The probability for Ms≥8.0 earthquake is the lowest, merely 0.0718.