A co-precipitation method was used to prepare a series of Co3O4 supported gold nanoparticles (Au/Co3O4), which were subsequently evaluated on their performance for "one-pot" synthesis of tricyclodecanedimethylol (TDDMO) from dicyclopentadiene (DCPD). Characterization methods including FTIR, XPS and TG-DTA were performed on the Au/Co3O4 catalyst during the course of reaction to reveal that three distinct stages of catalysis occurred while the catalyst possessed different physiochemical properties. The "one-pot" synthesis of TDDMO was successfully realized with selectivity over 90% under relatively mild reaction conditions of 140-150 degrees C reaction temperature and 7-9 MPa pressure. Experimental data suggested that the catalytically active species might be a Co(CO)(x)(PPh)(y) complex where the presence of gold can assist the in situ reduction of Co3O4 to metallic cobalt under reaction conditions, thereby increasing the number of active sites. Another role of Au was proposed as facilitating hydrogenation of an in situ formed intermediate aldehyde, diformyltricyclodecanes (DFTD), to produce the final product TDDMO.