With the European standard samples as benchmark, three soil digestion methods for measuring total mercury in topsoil were compared and studied. They are:(1) concentrate HNO₃ and concentrate HCl (1:3), and (2) concentrate HNO₃, concentrate H₂SO₄, and KMnO₄, (3) H₂SO₄ (1:1) and KMnO₄. They are all applicable. The soil in the surroundings of the garbage-fueled power plant was investigated for mercury background value in the top soil. Results show that it reached 192.68 ng/g, in Pudong, significantly higher than that in any other cities, which may be related with the histories of the local industry and the fertilization in agriculture. What should be noted is that the content of gaseous mercury in the soil was also very high ranging from 10.69%~92.06%, with a mean value of 48.73%.