Abstract: Through the observed data of the rupture direction of an earthquake of magnitude Ms > 4.6 and the pattern of temporal-spatial distribution of seismicity before the M = 7.2 earthquake occurred on March 22, 1966 in the Xingtai region, it may be revealed that there exist a Barrier somewhere near the town of Lianzizhen. This barrier is supposed to be an important factor controlling the seismicity during this period.