In the research, HNO3-HClO 4 method and Tessier method were chose to extract the total content and chemical form of Pb、Zn in the total suspended particles (TSP) in both heating period and non-heating period. The pollution characteristics of Pb、Zn in TSP of Xi’an was analysed by discussing their total content、chemical form and the distribution characteristics of bioavailability. The result indicated that in the heating period, total content of Pb in January was bigger then it in February and residual was the advantage state. Total content of Zn changed greatly and the highest level appeared in January and the advantage state was exchangeable. However, in the non-heating period, the highest level of Pb、Zn appeared in June and April respectively, and the lowest level appeared in April and May. In this period, the advantage state of Pb、Zn was bound to carbonates and its distribution characteristics of bioavailability was contrary to it in heating period.