Based on data of earthquake sequences with MS≥6. 0 in Chinese mainland and the border region since 1966，the paper studies different rupture types of the main shock and aftershock sequence characteristics under different fracture types． We obtain the experiential formula of the different proportion of aftershock，distribution of advantage，magnitude difference between main shock and maximum aftershock under different fracture types． Main shock magnitude and maximum aftershock magnitude have good linear relationship，and this kind empirical formula can provide the reference for the determination of maximum aftershock magnitude in Chinese mainland． The occurrence of maximum aftershock within 10 days after the main shock is 43. 8% ～ 81. 8%，while that of isolated maximum aftershock of strike-slip type and normal fracture type within 10 days after the main shock is up to 80% ．