Objective To study the complication of artificial liver support system(ALSS) on treating patients with chronic severe hepatitis. Methods The complications of 159 chronic severe hepapatients who received 310 times ALSS therapy were investigated. Results During the process of treatments, 78 times of side effects were found(25.2%). Most of them was plasma allergy (18.1%), the second was intractable transmembrane pressure increase(4.5%). The most severe complication was hypotension(0.97%). Of all patients, most were relieved after treatment. Conclusions Artificial liver support system has been proved to be safe and effective in treating chronic severe hepatitis, prevent and treat the complications actively are the most important measure to obtain success.