Abstract: Abstract: The utilization of renewable resources has been given more attention in the past decade due to the growing shortage of fossil fuels and the worsening of global climate problems. Biomass, including wood residues and agricultural residues, is one of the most promising renewable resources due to wide distribution, large yield, and renewability. Pyrolysis is one of the most appropriate thermochemical processes and can convert biomass into bio-oil, bio-gas, and bio-char. In order to use pyrolysis pathway of corn stalk more efficiently, analytical Py-GC/MS (pyrolysis-gas chromatography/mass spectrometry) experiments were performed at 300, 400, and 500℃ to investigate the pyrolysis characteristics and product distributions of the corn stalk fractions (including stem bark, leaf, ear husk, and stem pith) and explore the effects of chemical inhomogeneity on pyrolysis behaviors of the corn stalk fractions, as well as determine the effects of pyrolysis temperature on the product distribution. The results indicated that the pyrolysis characteristics of the corn stalk fractions differed remarkably from each other and were influenced differently by the pyrolysis temperature. With an increase in pyrolysis temperature from 300 to 500℃, total yields of volatile products including phenolics, furans, linear aldehydes, linear ketones, anhydrosugars, linear acids, and others increased from all samples. However, the changes of the total yields of volatile products were different among samples. The most increase from total yields of volatile products was obtained from stem pith at 300℃ and from stem bark at 400-500℃, which suggested that the pyrolysis progress of stem pith germinated more easily at a lower temperature. The total yield of volatile products of ear husk was the lowest at every pyrolysis temperature. At 300℃, the highest value of phenolics content in pyrolysis products was 29.76% from stem pith and the lowest value was 13.97% from ear husk; the highest furans value of 12.34% was from whole corn stalk and the lowest value of 7.60% was from ear husk. At 500℃, the most linear aldehydes content of 18.40% was obtained from leaf, the stem pith was degraded into more linear ketones at 12.45%, and the anhydrosugars content at 4.31% was the highest value from stem bark. The identified chemical compounds contents in the pyrolysis products were different according to the pyrolysis temperature among samples. The 4-vinyl phenol (4-VP) content at 21.27% was the highest from stem pith at 300℃, which suggested more pyrolysis selectivity for 4-VP. However, stem bark pyrolysis could obtain the highest 5-hydroxymethyl furfural (HMF) content of 6.61% at 300℃. At the pyrolysis temperature range of 400-500℃, the most feedstock in corn stalk fractions to form hydroxyacetaldehyde (HAA) and 1-hydroxy-2-propanone (HA) was the leaf. Ear husk as feedstock could be a good selection for product bio-oil due to low acetic acid (AA) in the pyrolysis product. Chemical inhomogeneity among corn stalk fractions could be the main reason for their pyrolysis characteristic differences. Biomass fractions should be given optimum applications in the future. The research results will provide a theoretical basis for using high value biomass and develop a new road of biomass selective pyrolysis.