Mercury and Arsenic in urban soils are highly noxious elements because of their potential impacts on urban environment and public health,and there are paid more attention by scientists in the world.A total of 425 sampling sites were selected in different administrative districts of Guangzhou.These sites included the Tianhe,Yuexiu,Baiyun,Haizhu and Liwan districts,and represented several land uses such as urban parks,residential sites,roadsides,and industrial sites in urban areas.Composite soil samples collected at a depth of 0-10cm were obtained by mixing subsamples from five random points within lm2 in each sampling site,and soil Hg and As concentrations and their pollution index were studied in this paper.The results indicated that Hg and As concentrations in urban top soils vary greatly in different sites.Mercury concentration is between 0.013 and 12.231 mg.kg-1,averaging 0.614 mg·kg-1,Arsenic concentration is between 1.40 and 143.98 mg.kg-1,averaging 17.35 mg.kg-1.Compared to the background Hg (0.157 mg.kg-1) and As(17.4 mg.kg-1) values of soils in Guangzhou,only a quarter of soil Hg concentration is less than the background,more than a half of soil Hg concentration is over two times as it was,and about 63% of soil As concentration is less than the background,only about 5% of soil As concentration is over two times as it was.The mercury pollution in Guangzhou urban soils is serious.Mercury and As in topsoils have obvious regional differentiation characteristics,which are highest in Yuexiu district,the oldest city area,and urban parks.The Hg and As pollution of soil in urban parks should be paid more attention to their influence on human health.