Objective To investigate the causation for exceeding hygienic standard of aerobic bacterial count in cold drinks. Method Simulating temperature fluctuations in the process of stockpiling and transporting cold drinks; and simulating a rather high temperature of preparing raw materials in workshop. Aerobic bacterial counts of three cold drinks named vanilla ice cream bar, mungbean ice cream bar and pineapple ice lolly bought from market or self-made were detected on different steps of operation. The Gompertz model was used to describe the growth rate of bacteria. Results The propagation of microorganisms in cold drinks was not significant at temperatures fluctuating between -18～4℃ in a short period of time if the initial bacterial counts were rather low. If the raw materials were exposed to 30℃ for more than 7h, the aerobic bacterial counts would exceed the hygienic standards or reach to a rather high level. Gompertz model is well fit for predicting the propagation trend of microorganism in ice cream bars at these circumstances. Conclusion The aerobic bacterial count exceeding hygiene standards in cold drinks is mainly due to bad hygienic circumstance in the workshop instead of the temperature fluctuating in the process of stockpiling and transporting.