This paper was focused on the evaluation of the feasibility and specificity of fluorescence in situ hybridization(FISH) method in the detection of the total bacteria in Fast-frozen Dumplings,and the construction of a fast,accurate and convenient detection system.TAMRA-labeled EUB338 probe was used to optimize the FISH detective conditions,and eight kinds of Fast-frozen Dumplings samples were detected by FISH to test its effect.After the optimization,the ideal Fast-frozen Dumplings sample preparation conditions were obtained as follows: 2h thermal fixing-time,20min of 4% poly-formaldehyde fixing-time,and 5min of ethanol dehydration time.The hybridization conditions were as follows: hybridization at 46°C in 20% formamide for 3h,with the dilution concentration of 225mmol/L NaCl.The testing results suggested the total amounts of bacteria from 2 samples out of 8 were exceeding the Food-standard.FISH can be effective for the detection of the total number of bacteria in the Fast-frozen Dumplings,which will provide more theoretical support for the food safety detection.