Abstract: Feasibility of using water hyacinth juice for methane production in a 10 L stirring tank reactor(CSTR) at 35℃ was studied.The entire process took 40 days,and the organic loading rate was increased step by step from 0.5 kg CODm-3d-1 to 5 kg CODm-3d-1.The CSTR started up quickly,and after 30 days,the organic loading rate reached 5 kg CODm-3d-1 with 75% COD removal rate.HRT was reduced by half,from 5 days to 2.5 days,while the volume biogas production rate reached 1.1 m3m-3d-1 with a methane content of 65%.In processing,the effluent pH was stable between 7.2-7.6,indicating that the reactor was adequate in handling the increased organic loading.The results suggested that water hyacinth juice could be used as a substrate for methane production,and that the CSTR anaerobic digestion system could be effectively employed for the application.