4-Ethyl guaiacol was selectively produced from catalytic fast pyrolysis of softwood biomass using Pd/SBA-15 catalyst. In-situ catalytic pattern performed much better than ex-situ pattern on 4-ethyl guaiacol production. Certain holocellulose-derived compounds might act as hydrogen-donors for the formation of 4-ethyl guaiacol. The maximal 4-ethyl guaiacol yield reached 18.44xA0;mg/g.