Objective To study the effect of p38MAPK on the activity and c-myc protein expression in rat acetaldehyde-induced hepatic stellate cell(HSC),and to investigate the alcoholic liver fibrosis related mechanism.Methods The different concentrations of SB203580 as the p38 specific blocker was adopted to conduct the intervention on rat acetaldehyde-induced HSC.The cellular mor-phological change was observed by the microscope.The cell proliferation was detected by MTT,the cell cycle was analyzed by flow cytometry(FCM),and the expression of c-myc protein was examined by the SABC method.Results (1)after acetaldehyde stimula-tion,HSC was increased in size and proliferated rapidly,but with the added SB203580 concentration increase,the cellular prolifera-tion was slowed down,the cells size was diminished and the deformed cells were increased.(2)The proliferation of acetaldehyde-in-duced HSC was inhibited by different doses of SB203580,and the higher concentration has the more significant inhibiting effect.(3) With the SB203580 concentration increase,the cells at the phase G0 and G1 were increased,while the cells at the phase S were de-creased,at the same time the expression positive rate of c-myc protein was decreased.Conclusion Blocking p38MAPK pathway ac-tivity could inhibit the proliferation of acetaldehyde-induced HSC,which may be related to the down-regulation of C-myc protein ex-pression and blocking the DNA synthesis in cells entering from G0/G1 phase to S phase.