Laccase3 is an important virulence factor and induced by the presence of tannic acid, a group of phenolic compounds function as a natural barrier against pathogen infection. Heat shock protein 24 in Cryphonectria parasitica contributes to the stress adaptation and virulence of a eukaryotic pathogen. In the previous study, the expression pattern of CpHsp24, induced by tannic acid and hypovirus, was similar to that of laccase3 and the accumulation of lac3 transcript in response to tannic acid supplementation was hampered in the CpHsp24-null mutant. It is tempted to speculate that CpHsp24 might function as a molecular chaperone for the protein product of the lac3 gene. The focus of the current study was to examine whether the protein product of the CpHsp24 gene plays a part as a molecular chaperone for the LAC3 protein. Two genes were cloned and co-expressed using Saccharomyces cerevisiae heterologous expression system and initial attempt of binding was performed using GST-fusion based assay. The specific functional interaction of LAC3 with heat shock protein 24 was validated by laccase assay using the tannic-acid supplemented medium and spectrometric assay using DMOP as a substrate. The co-expressed transformants showed darker brown coloring and higher enzyme activity, whereas less color reactions were observed in single gene expressed cells. These findings suggest that the molecular association of heat shock protein 24 with LAC3 may contribute to pathogenesis.