In view of the range extended and flight space enhanced substantially of new rockets, the varying law of the major aerodynamic characteristics of the fin stabilized rocket following accretion of altitude above sea level and its influence to the ballistic characteristic were studied in this paper. The conclusion shows that more attention should be paid to the influences applied by the drag coefficient increase and the center of pressure coefficient decrease following the accretion of the altitude above sea level to the ballistic characteristics. For the long range rocket with flight trajectory high than 30km, the aerodynamic coefficient varying following accretion of the altitude should be considered in power design and ballistic simulation.