With the great development of automobile industry and road system, the pollution of automobile exhaust becomes more and more serious, also mercury pollution. Burning mercury-rich fuel oil was thought the essence of pollution source. It's found that elemental mercury (Hg0), divalent reactive gaseous mercury (RGM), and particulate mercury (Hg (p)) from gasoline. The content of mercury is LPG>;gasoline>; diesel fuel. The forming condition of oil-gas field was obviously similar to mercury ore site, and thus assessment of oil-gas field their mercury contents should be measured. The study of seven road sections of Guilin demonstrated that there are obvious mercury pollution in atmosphere, soil and plants.