[Objective]To explore the regulatory effect of Chinese herbal fermentation preparations on alleviating heat stress in dairy cows and the nutritional regulation measures to alleviate heat stress in dairy cows. [Method]Forty healthy,disease-free,and even animals with similar parity were randomly divided into four groups: control group,test group I,test group II, and test group III. There were five replicates in each group,and two animals in each replicates. Cows in the control group were fed with the basic diet,and 1%,2% and 3% Chinese herbal fermentation preparations were added to the basic diet in groups Ⅰ,Ⅱ and Ⅲ respectively. [Result]The results of physiological indexes,lactation performance and serum biochemical indexes showed that rectal temperature and respiratory frequency of heat stressed dairy cows were significantly reduced,average daily gain and average daily feed intake were significantly increased,and feed weight ratio was significantly reduced （P<0.05）.The milk yield,milk fat rate and milk protein rate of dairy cows increased significantly,and the number of somatic cells decreased significantly （P<0.05）.The contents of albumin,total protein,urea nitrogen, blood glucose,glutamic pyruvic transaminase and glutamic oxaloacetic transaminase in dairy cows increased significantly（P<0.05）.Chinese herbal medicine fermentation preparation can effectively alleviate the heat stress of dairy cows,restore normal physiological and serum biochemical index levels,and improve the lactation performance of dairy cows. [Conclusion]The Chinese herbal medicine fermentation preparation can effectively alleviate the heat stress of dairy cows,restore the normal physiological and serum biochemical index levels,and improve the lactation performance of dairy cows. Under the experimental conditions,the appropriate addition amount of Chinese herbal medicine fermentation preparation in the diet is 3%.