Abstract: The production of podophyllotoxin, a precursor of anti-tumour drugs, was investigated in Juniperus chinensis stem-derived callus cultures on modified SH medium. The SH medium containing half strength of ammonium dihydrogenphosphate, NAA (3mg/L), kinetin (0.2 mg/L) supported the calli growth without differentiation and production of podophyllotoxin. The content of podophyllotoxin in the calli grown on the medium was three times higher than that of the intact plant. The production of podophyllotoxin in stem-derived callus cultures were increased by addition of biogenetic precursors, phenylalanine, coniferyl alcohol and a biotic elicitor, chito-oligosaccharides (COS). Podophyllotoxin production was stimulated to 6.4, 3.6, and 2.2 fold by addition of COS, phenylalanine and coniferyl alcohol, respectively. To find an active compound in the COS for stimulation of podophyllotoxin production, composition of each constituent in the COS was analyzed by HPLC. Chitopentaose was found to be the most active compound for stimulation of podophyllotoxin production in stem-derived callus cultures.