Abstract: The results from this study indicate that there are 50 kinds of volatile organic compounds (VOC's) with particle size of 15-80 mm during MSW composting, including 5 kinds of sulfur odor compounds, 25 kinds of hydrocarbon compounds, 14 kinds of aromatic compounds and 6 kinds of other odor compounds. The correlation analysis show that the odor concentration is significantly correlated with the emissions of sulfurated hydrogen, dimethyl sulfide, carbon disulfide, methyl disulfide, 1,3-dimethyl and o-xylene (p<0.01). Considering of the detection olfactory threshold of all odor compounds, priority control sequence of the odors were sulfureted hydrogen>dimethyl sulfide>methyl disulfide>carbon disulfide>1,3-dimethyl> o-xylene. With the low olfactory threshold of methanthio, even if the emission concentration was very low, it would produce serious odor pollution. Furthermore, NH3 contribution to odor concentration was relatively small, but its emissions were relatively high. It should also focuse on monitoring and control of the methanthio and NH3 during the particle size of 15-80 mm MSW composting. This study can provide a reference for monitoring of odor substances and making control strategy.