Abstract:To set up a new method of detecting bacterial number in situ, NADH fluorescence method based on the fluorescent characteristic of NADH was used. When the concentration of NADH ranged from 10 nmol/L to 0.2 mmol/L, its concentration had a good line relationship to the fluorescence intensity(R2= 0.9905). Separating bacterial cells by centrifugation and extracting NADH with hot Tris-HCl buffer, the result of bacterial count detected with NADH standard plot was 1×104 CFU/mL in an hour. In summary, NADH fluorescence method is rapid, sensitive, simple and reliable to detect total bacterial number. Therefore, the method can be widely applied in the field of food sanitation and safety, environment detection and so on.