Abstract: In this study, 15 high-yielding and 15 low-yielding Dehong dairy buffaloes were selected to compare their heat tolerance ability based on the collected DHI data. The experiment was conducted in the feeding environment with THI value of above 72, and the period of the experiment lasted for 27 d. At the end of the experiment, the milk yield, milk quality, and the hormone concentrations and physiological parameters associated with heat stress of the high-yielding and low-yielding Dehong dairy buffaloes were determined and statistically evaluated. The results revealed that the number of somatic cells of low-yielding Dehong dairy buffaloes was significantly higher than that of their high-yielding counterparts （P〈O.05）, but the content of non-fat milk solids of low-yielding group was significantly lower than that of high-yielding group （P〈O.05）. No significant differences in the other milk quality evaluating indexes between the two groups were observed. Under the heat stress, the concentration of ACTH in low-yielding Dehong dairy buffaloes was significantly lower than that of high-yielding group （P〈0.05）, but the concentrations of Cor, INS and T3 of low-yielding group were relatively higher. Based on the above results, we cannot draw the conclusion that there are differences in heat tolerance between high- and low-yielding Dehong dairy buffaloes.