Abstract: Component of bio-oil form Larchwood by fast pyrolysis technique was completely analyzed in order to make more rational and high efficient use of new adhesive agent making by the bio-oil of Larchwood and phenolic resin. Qualitative determination of bio-oil of Larchwood was performed by Gas Chromatography-Mass Spectrometric (GC-MS) method. The study on quantitative analysis of the polyphenols in the bio-oil was used by Gas Chromatography (GC). Fourier transform infrared spectroscopy (FT-IR) was applied to characterize structure of heavy oil that were obtained through the bio-oil evaporated by rotary. Components of the bio-oil were disclosed through analyzing, which included acids, ethers, phenols, alcohols, aldehydes, alkanes, as such complex organic compounds. Results revealed content of phenols in bio-oil were ranged from 4% to 15%, maximum content was 14.15% under different treatment conditions.