Abstract: The authors investigated the active faults in the Linfen basin,Shanxi Province and discovered many earthquke defortmation traces in the foreland of mountains from the Hongdong county to Huo county on the eastern boundary of the Linfen basin.We considered that these were the result of Ms = 8.0 earthquake of 1303.The discoveries are likely to provide new data for further study of the earlest Ms = 8.0 earthquake drcumented on the historical record.In this paper.We have described the earthquake deformation traces discovered in good detail,and made a preliminary discussion of problems concerning the great earthquake of 1303.