Back ground and Objective : There is a need for objectification and scientific verification of Pattern identification in Oriental medicine. The purpose of this study was to investigate the skin characteristics of Qi deficiency and Blood deficiency animal models. Material and Methods : Sprague-Dawley rats were divided into three groups: normal group, Qi deficiency group and Blood deficiency group. The Qi deficiency animal model was induced through restriction of food (75g/kg/day) for 20 days. Blood deficiency animal model was induced by bleeding from tail vein(0.3 ml/time) 8 times. The normal animal model was kept without any intervention. The general condition was observed by measuring body weight, body temperature, blood pressure, pulse rate, and hematological and biochemical parameters. The skin characteristics were observed by measuring the erythema index(EI), melanin index(Ml), transepidermal water loss(TEWL) and dermal microcirculation. Results : 1. In the Qi deficiency group, body weight was lower than the other groups. In the Qi deficiency group, blood pressure was lower than in the Normal group. There was no difference in body temperature and pulse rate between the three groups. 2. In the Qi deficiency group, blood sugar was lower than in the Blood deficiency group. There was no difference in triacylglycerol between the three groups. In the Qi deficiency group, the WBC count was lower than in the Blood deficiency group. RBC count was highest in the Qi deficiency group, Normal group and Blood deficiency group respectively. In the Qi deficiency group, Hb and Hct were higher than the other groups. 3. EI and MI were decreased in the Qi deficiency group, and EI showed a significant decrease. 4. EI and MI were increased in the Blood deficiency group, and MI showed a significant increase. 5. TEWL was significantly increased in the Qi deficiency group, while it was decreased in the Blood deficiency group, TEWL was highest in the Qi deficiency group, Normal group and Blood deficiency group respectively and all three groups showed significant difference. 6. In the Qi deficiency group, dermal microcirculation was lower than the other groups. Conclusion : The above results show that the erythema index decreases in the Qi deficiency model, and the melanin index increases in the Blood deficiency model. The Qi deficiency animal model shows an increase in transepidermal water loss, while the Blood deficiency animal model shows a decrease. Further studies should develop new models of Pattern Identification that are more specific.