Abstract: The occurrence of the M_S5.9 earthquake between Balinzuoqi and Alukerqinqi on Aug.16, 2003 turned the seismic activity in the eastern Inner Mongolia into another active stage.The analysis to the earthquake sequence indicated that the variation in space of these earthquakes was not large.That these earthquakes distributed in a small region meant the stress in the area was relatively concentrated.The zone formed by the whole sequence was mainly in NWW direction, and its strike was accordant with the direction of major axes of macro-intensity and the principal compressive stress direction of its focal mechanism solution.Thus we concluded that we should pay more attention to the seismic development in northeast Inner Mongolia in future 1~2 years.