Objective To study the effect of heart rate and behavior changes in Labrador retrievers determined by distance test (DT), and to provide effective behavior methodological and physiological basis for early screening of guide-dogs. Methods Sixty Labrador retrievers (8-15 months old; 22 females and 38 males) were provided by Chinese guide dog training centre of Dalian. 30 of the 60 dogs were guide dogs and the other 30 were eliminated dogs which were evaluated by examination in the training center. The "interest", "exploration" and "play invitation" behavioral categories in the distance test (DT) of the dogs were tested and the heart rates were simultaneously recorded. Results The mean heart rate of the guide dogs were significantly lower than those of the eliminated dogs during the DT (P<0.05). The scores of "interest", "exploration" and "play invitation" showed no significant difference between the guide dogs and eliminated dogs (P>0.05). Conclusions In the distance test, the changes of heart rates in guide dogs are significantly lower than eliminated dogs. The results of this study indicate that guide dogs have a more stable psychological quality and better control of emotions compared with eliminated dogs in the DT. Our study may provide a theoretical basis for the combination of DT and heart rate to predict the success rate of the guide dog training.