The obvious difference of air pollution change rule in new year eve night of forbidden and not forbidden zones before the forbidden limit of cracker firing; and the change character after the limit were in these zones; meanwhile, the air pollution state in 2000-2006 spring festival period was evaluated. The concentrated firing of a large amount of cracker created serious air pollution at short time; but the pollution state was improved rapidly with less cracker firing. There existed different influence of cracker firing on different air pollutant. PM10 pollution was the most serious; the concentrations of SO2, NOx was also enhanced obviously; while existed definite stagnant of CO, even without obvious response. Obvious firing pollution top peak existed in not forbidden zone before the forbidden limit; while not appeared in forbidden zone. Besides, the influence of cracker f＇tring on the small particles of air was most remarked; and not great on the crude particles, specially the particles of 10-20mm diameter. The decrease of industrial and vehicular transportation pollution discharge during the Spring Festival period caused the improvement in air quality. In January 1^st-15^th of Chinese calendar, 2000-2006, PM10 concentration was 16% and 20% lower than the wintertime and annual averages, which was influenced by meteorological condition.
China Environmental Science