Abstract: Objective To investigate the causative relationship between smoking and the occurrence of primary biliary cirrhosis（PBC）. Methods A questionnaire survey-based,and gender-and age-matched case-control study,was carried out. 109 patients with PBC and 218 healthy volunteers were consecutively recruited at Xijing Digestive Disease Hospital from 2009 to 2014. ResultsThe total consumption of cigarettes in patients with PBC was remarkably higher than that in controls[（P25 32393.8,P75 134137.5） vs.（P25 22356.3,P75 104025.0）,P<0.01];the median consumption of cigarettes in patients with PBC was also higher than that in controls （93075.0 vs. 76650.0,P<0.01）;The age of first exposure to smoking and total lasting time of smoking in patients with PBC were（19.5±2.7） years and （24.3±8.1） years,respectively,much younger or longer than（23.7±6.4） years and （23.1±9.3） years in controls;the average daily consumption of cigarettes in patients with PBC were（5.0,15.0）,while they were （2.5,11.3） in controls （P>0.05）;There existed no differences between the two groups as respect to the history of smoking or passive smoking,age of first exposure to passive smoking,total lasing time of passive smoking,the daily consumption of passive smoking and the total consumption of passive smoking,neither in the sum consumption of smoking and passive smoking. Conclusion Smoking may serve as a vital risk factor for the development of PBC.

Key words: Primary biliary cirrhosis, Smoking, Risk factor, Dose cumulative effect