The odor pollution of landfill is one of seriously pollutions in city ambient area. Main pollution points in the landfill area have been detected by preliminary research. For a particular purpose to recover the materials changing in odor dispersion process and to find out odor indication material, GC-MS method was used to detect materials in the different site at down wind direction. Then, similarity coefficient of VOCs (volatile organic compounds) composition between every two site were calculated and compared to look for changing regular of odor pollution in diffusion process. The odor pollution indictor material has be found in the materials that appeared in down wind direction of operation area and compared its' olfaction threshold. The results show that: there have 19 types of common materials in the landfill area, including monoaromatics, alkanes and halogenated compounds; Materials in the air of operation area site has marked influence on down windward direction air of landfill, and m-xlyene has been selected as odor pollution indictor of landfill air by this research.