Abstract: By analyzing the SO₂,NO₂ and PM10 indices in Guangzhou from January to June 2003, we have the following findings.(1) The variations of SO₂, NO₂ and PM10 have very good synchronal relations with one another. Among them, NO₂ and PM10 show the highest correlation. (2) From the monthly-averaged index values,the PM10 seems to be the main polluting substance for the whole period, followed in sequence by SO₂ and NO₂(except in January). PM10 and NO₂ tend to decrease sequentially with month. Yet SO₂ remains at a stable level; The variations of PM10 are analyzed in detail. (3) For the monthly variances, the maximum variances of SO₂, NO₂ and PM10 appear in January. The second maxima occur in February. (4) Some surface pressure patterns relevant to air pollution are presented. Stronger wind in the cold front resulted in lower pollution. The in-ridge refluence may be considered as main mechanism resulting in high air pollution. When it turned from calm weather into southeasterly (to be more accurate, from easterly to southerly) , the pollution indices might increase.