Aim To study the mechanism of andrographolide(AD) on the proliferation and apoptosis induction in human esophageal cancer Ec9706 cells.Methods The spectrometry was used to detect the activity of caspase-3 in human esophageal cancer Ec9706 cells treated with or without AD for 6 h,12 h and 18 h,and to detect the activity of caspase-8 and caspase-9 in human esophageal cancer Ec9706 cells treated with or without AD for 6 h.The influence of AD on the proliferation of Ec9706 cells after treatment with or without Z-VAD-FMK(a broad-spectrum caspase inhibitor) was determined by MTT method and the result was compared.The changes of gene expression levels of bcl-2 were determined by immunohistochemical method.Results The expression level of bcl-2 gene was obviously lower in the cells treated with AD(30 mg?L-1,P