Abstract：In order to study the effects on biological bodies of a dry and cold environment, several male ICR mice were put under a dry and cold condition to simulate Xinjiang's unique dry and cold environment, to establish a mice model of northwest dry and cold syndrome for the first time in China based on the theory of traditional Chinese medicine. After 21 days, the animals organs were taken out in order to observe histological changes by optical microscopy, and to observe ultra-structural changes by electron microscopy, and a comparison is made between two groups. Monoamine neurotransmitters were determined with reversed phase ion pair (RP-IP)-HPLC and results are compared between normal control group and dry and cold group. The morphological changes are mainly in the blood vessel's mild expansion, and cell's ultra structural changes are mainly in edema. After the stressing of 21 days of dry and cold environment, the quantity of norepinephrine (NE) and dopamine(DA) in serum was significantly lower than that in the normal control group (P<0.01), while the quantity of 5-HT was higher(P<0.05). But in brain, they are all in a lower quantity than the normal control group. Dry and cold environment can lead to the appearance of a kind of symptom (Qi) related to dry and cold, so it may be concluded that dry and cold environment is one of the most imporment causes of northwest dry and cold syndrome; and the disorder of the northwest dry and cold syndrome is related not to just one organ but the body as a whole, with systemic, systematic changes.