Plants synthsize a number of PR(pathogensis related) proteins in response to pathogen invasion and environmental stresses. We have cloned and determined the nucleotide sequence of a cDNA encoding the basic chitinase, a PR protein, from oligosaccharide-treated rice cell. Synthetic oligo-nucleotides prepared from N-terminal region of Hevein domain in rice chitinase were used as probes for the screening of cDNA library. A full-length chitinase cDNA whose size was 1109 bps and which had 54 bps of leader sequence for signal peptides was isolated. Northern blot analysis showed that the chitinase transcripts were most highly accumulated at 8 hrs after elicitor-treatment and that their size was about 1,200 nucleotides. However, chitinolytic activity of protein chitinase was highest after 48 hrs induction.