Abstract: On the basis of the historical documents collected and the record on the tablet discvered during surveying the historical earthquake area recently, this paper analyses the intensity, magnitude, location, and the affected area of the earthquake occurred in the first year of Chongzhen in Ming dynasty period(Oct. 7, 1628) in the area of Xiyanghe-Dukoubao in Huaian county of Hebei Province. The parameters of this earthquake are estimated as follows: Occurrence time, Oct, 7 1628 Epicenter coordinates: 40.6°N, 114.2°E Epicenter intensity. Ⅷ Magnitude: 6(1/4)