Abstract: The HALOE trace gases data from 1992 to 2005 show that NOx and ClOx play different roles in the ozone photochemical destruction in the stratosphere. The simulations with SOCRATES3 model indicate that: (1) The ozone depletions of polar areas in summer are mainly attributed to the chemical process of NOx; (2) the ozone variations in the Northern sub-polar areas in spring and in the Southern sub-polar areas in winter are mostly contributed by the dynamical transportation. This study also shows that the photochemical mechanisms of ozone loss in the Antarctic and Arctic stratosphere in spring are different. Heterogeneous reactions of polar ClOx and homogeneous reactions of sub-polar NOx regulate the ozone loss in the Antarctic areas in spring. However, homogeneous reactions of ClOx and NOx dominate the ozone loss in the Arctic areas in spring. The analyses of the contributions of the dynamical transportation and the photochemical process to the ozone show that 45% of the variation in the entire lower and middle stratosphere and the tropical upper stratosphere is attributed to the dynamical transportation, and 65% of the variation in the upper stratosphere at high latitudes is attributed to the photochemical process.