Abstract: Based on the data of the sandstorm weather almanac and the data of observed particulate matter concentration, the quantitative index of sandstorm effect on environmental quality was defined. Meanwhile, the sandstorm effect on air quality in source areas and affected areas were analyzed using this quantitative index. Moreover, the difference of impacts in the urban and rural areas in Beijing was analyzed. The results showed that:1) The annual average contribution rate of the sandstorm effect on Hohhot which is near the source areas was 6.84%, on Beijing which is the affected areas was 5.96%, on Tianjin was 3.57% and on Jinan was 1.66%, from 2001to 2009respectively. 2) The maximum contribution rate of the sandstorm effect on source areas and affected areas was on March with 19.21% of Hohhot, 15.02% of Beijing, 9.14% of Tianjin and 8.69% of Jinan. 3) The absolute contribution of the sandstorm effects on Beijing''s air quality were serious in April of 2000and in March of 2001with 0.062and 0.077mg/m^{3respectively}. The proportions of the national second grand standard of the ambient air quality (0.15mg/m³) were 41.3% and 51.3%. 4) The sandstorm effect on the urban and rural areas of Beijing was not completely consistent.