Anaerobic digestion of Chinese cabbage waste was investigated through a pilot-scale two-stage digester at a mesophilic temperature of 37 degrees C. In the acidification digester, the main product was acetic acid, with the maximum concentration of 4289 mg.L-1 on the fourth day, accounting for 50.32% of total volatile fatty acids. The oxidation reduction potential (ORP) and NH4+-N level decreased gradually with hydraulic retention time (HRT) of acidification. In the second digestion phase, the maximum methanogenic bacterial concentration reached 9.6 x 10(10) ml(-1) at the organic loading rate (OLR) of 3.5-4 kg VS.m(-3), with corresponding HRT of 12-16 days. Accordingly, the optimal biogas production was 0.62 m(3).(kg VS)(-1), with methane content of 65%-68%. ORP and NH4+-N levels in the methanizer remained between -500 and -560 mV and 2000-4500 mg.L-1, respectively. Methanococcus and Methanosarcina served as the main methanogens in the anaerobic digester. (C) 2015 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. All rights reserved.