Objective To explore the stability of body constitution of rats with special cold and heat constitutions and the influence of Chinese medicines on them.Methods The skin temperature of the posterior palms and the autonomic activities of rats were tested and the general state of rats were observed to identify the rats with special constitutions.Ten rats with Normal

9 rats with Cold and 8 rats with Heat constitution were selected from 100 rats.After the tests in succession for 3 months

the rats in Cold and Heat constitution groups were treated with the decoction of Jingui Shenqi Wan （Kidney Qi Tonifying Pill） and Zhibai Dihuang Wan （Eight Flavor Rehmanni） respectively for three months.The changes in the related indices were observed 4 months after stopping medication.Results During the 3 months without treatment after body constitution selection

the palm temperature and the autonomic activities of the rats in Cold constitution group were significantly lower than those of Normal constitution group.The related indices of the Heat constitution group were significantly higher than those of Normal and Cold constitution groups（P<0.05 or P<0.01）.And this difference remained in the observed 3 months

i.e.the specialized difference of the Cold and Heat constitution of rats was steadily existing under the situation without treatment.Jingui Shenqi Wan and Zhi Bai Dihuang Wan functioned to regulate the Cold and Heat constitutions of rates respectively

making the palm temperature and autonomic activities of rats in the Cold constitution group increased and those decreased in the Heat constitution group.From the third month after stopping using the medicines

there was a tendency that the above-mentioned indices were back to level of before medication.Conclusion The Cold and Heat constitution of rats was stable relatively.