OBJECTIVETo observe the anti-tumor effect of alcohol extract of Stellera chamaejasme-AESC, AESC-1 and AESC-2 in vitro.METHODInhibition rates of AESC, AESC-1, AESC-2 on five tumor cells (A549, NCI-H157, NCI-H460, BEL-7402 and SK-HEP-1 cell lines) were observed and IC50, GI50, TGI50 and LC50 were calculated with the methods of MTT and SRB.RESULTAESC, AESC-1, AESC-2 have inhibitory effect on all of 5 cell lines and have a certain time-dependent nature. On 72 hours, inhibition rates of 100, 200 mg x L(-1) of various extracts on each cell line (except A549) were between 64.82% and 92.27%. IC50 of AESC and AESC-2 on NCI-H460 and BEL-7402 cell lines is less than 20 mg x L(-1), IC50 of AESC-1 on SK-HEP-1 cell line is less than 20 mg x L(-1). The mean GI50, TGI and LC50 of AESC, AESC-1, AESC-2 on sensitive cell lines were less than 40, 90, 150 mg x L(-1) respectively.CONCLUSIONAESC, AESC-1 and AESC-2 all have significant anti-tumor effect and have the different sensitivity to different cell lines; AESC-2 has the similar anti-tumor manner to the AESC and the anti-tumor active fraction of AESC may be mainly present in the AESC-2.