On February 10,1624,or December 22 of the Tianqi Third year in Ming Dynasty,an earthquake occured in Jiangsu Province. Yangzhou had been identified as the epicenter of the earthquake in “Chinese earthquake catalogue “which was published in 1960,which was mainly based on the historical document as” More than 380 battlements and 20 barracks of city wall had collapsed in Yangzhou”. Recently,some scholars have conducted several research on the epicenter of the earthquake. Then an official report related the earthquake were found,which provides the new data for the study. After analyzing reliability of all data,the relatively reliable historical data are chosen. By comprehensive analyzing historic data,which include human feeling,the earth's surface deformation and the direction of earthquake sounds,etc.,the earthquake sequence is also summarized. Finally the epicenter is re-determined at 32.2°N,119.5°E,where is considered as the epicenter of M5 1/2 in April 3,1913 at “Zhenjiang,Jiangsu”,with the new magnitude M6 1/4.