Chitinase-producing strain HOA73 has been used to control plant diseases. However, the antimicrobial activity of its extracellular chitinase has not been fully elucidated. The major extracellular chitinase gene () from strain HOA73 was cloned and expressed in in this study. This gene had an open reading frame of 2,028 bp, encoding a protein of 675 amino acid residues containing a secretion signal peptide, a chitin-binding domain, two fibronectin type III domains, and a catalytic hydrolase domain. The chitinase (PeChi68) purified from recombinant exhibited a molecular mass of approximately 68 kDa on SDS-PAGE. Biochemical analysis indicated that optimum temperature for the actitvity of purified chitinase was 50ºC. However, it was inactivated with time when it was incubated at 40ºC and 50ºC. Its optimum activity was found at pH 7, although its activity was stable when incubated between pH 3 and pH 11. Heavy metals inhibited this chitinase. This purified chitinase completely inhibited spore germination of two isolates and partially inhibited germination of spores. However, it had no effect on the spores of a isolate. These results indicate that the extracellular chitinase produced by HOA73 might have function in limiting spore germination of certain fungal pathogens.