Au/TiO2 catalysts were synthesized through Cinnamomum camphora leaf extract. The obtained catalysts were characterized through TEM, XRD, DRUV-vis and were used for CO oxidation. The influence of various parameters (Au loading, biomass, calcination atmosphere, and support crystal form) on the catalytic performance in CO oxidation was studied in detail. The experimental result revealed that under the conditions of 1.0 wt % Au loading, calcination atmosphere of air, TiO2 with mixed crystal of rutile and anatase, the Au/TiO2 catalyst exhibited optimum catalyitc performance, which remained its 90% CO conversion after 150 h.