Abstract: [Objective]In order to improve the accuracy of the detection of psychrophile bacteria in raw milk,a more reasonable standard process for the detection of psychrophile bacteria was developed.[Method]In this experiment,according to the MPC in NY/T 1331-2007 Determination of the Number of psychrophile Bacteria,Aerobic Spores and Thermophilic Aerobic Spores in Milk and Dairy Products,the level of psychrophile bacteria in a total of 120 raw milk samples from ten pastures with different cultivation modes in Xinjiang were detected at different detection times. [Result] Under the two dilution gradients of 10^-2 and 10^-3,the results of psychrophile bacteria in the three pastures of different modes increased with the increase of the detection interval,and there were significant differences between the results of psychrophile bacteria in the modern pastures and traditional large-scale pastures and the detection results of psychrophile bacteria in the 12 h and 24 h intervals（P<0.05）. There were significant differences between the immediate detection and 24 h interval of psychrophile bacteria（P<0.05）,but there was no significant difference between the detection results of 12 h interval and immediate detection and 24 h interval（P>0.05）.[Conclusion]The research results showed that the detection interval had an impact on the detection results of psychrophile bacteria in raw milk. The longer the detection interval,the larger the final detection results,resulting in the final results were not accurate and persuasive.

Key words: psychrophile, detection time, raw milk