The effect of carbon content of poplar charcoal on ignition temperature, moisture absorption, hydrogen content and volatiles content was studied. By using SEM, XPS, FT-IR, GC/MS, the appearance of surface, element contents, functional groups distribution and products of pyrolysis were characterized. Results show that charcoal contains a variety of macromolecular alkanes, functionalized polyunclear aromatic compounds,such as acids, ethers, esters, and phenols. Its stoichiometry is C₁₂H₄O₂ and the lowest ignition temperature is 184-186 ℃.