Abstract: Research of physical-chemical properties and Fourier Transform Infrared Spectrum (FTIR) analysis were conducted on bio-oil which was obtained through fast pyrolysis of poplar sawdust, apart from comparing with bio-oil from sweet sorghum stalk residues. The results showed that water content and heating value of bio-oil from sawdust was 25.01% and 20.62 MJ/kg, and its kinematic viscosity at room temperature, density, ash content and carbon residue content were 3.44 mm2/s, 1072 kg/m3, 0.305% and 12.74%, respectively. Simultaneously, the kinematic viscosity of bio-oil decreased significantly with the temperature increasing(25～100℃). With relatively low water content and high heating value, bio-oil from sawdust has wider application prospects than bio-oil from sweet sorghum stalk residues. However, a variety of functional groups inferred from the Fourier transform infrared spectra of different locations on the absorption peaks of bio-oil indicated that further refinery is required before its practical utilization.