Abstract: OBJECTIVE To investigate the distribution of culturable and non-culturable bacteria in hemodialysis water treatment system so as to accurately evaluate the microbiological safety of hemodialysis water.METHODS The counts of the culturable and non-culturable bacteria (including uncultured bacteria and VBNC bacteria ) were determined by means of plate count method and dead or viable bacteria fluorescent staining combined with confocal laser scanning microscopy (CLSM), and the physical and chemical indexes were analyzed via process operation.RESULTS The level of culturable bacteria met the related standards, however, the level of culturable bacteria was lower in the hemodialysis water than in the running water.The counts of non-culturable bacteria in different samples were 2~6 order of magnitudes higher those of the culturable bacteria, and the counts of non-culturable bacteria were about 10⁴cells/100 ml.CONCLUSIONThe culture method can not accurately reflect the distribution of bacterial colony counts in the hemodialysis water treatment system, most of the bacteria prevail in non-culturable state, which poses potential threat to the health of the patients.