Abstract: In order to investigate the effect of Ganmai Dazao decoction on the ethology, body weight, liver, muscle and small intestine morphological characteristics of simulated high temperature transport stress mice, in the experiment, 18 male healthy SPF-grade Kunming mice of similar weight at 1 month of age were randomly and equally divided into blank group, model group and Ganmai Dazao decoction group with six mice in each group. After the start of the experiment, the model group and the Ganmai Dazao decoction group were treated with an airtight container on a constant temperature shaker at 35 ℃ for 2 h at 160 r/min for 3 consecutive days. The Ganmai Dazao decoction group received Ganmai Dazao decoction by daily infusion, and the blank and model groups received equal amounts of normal saline for 7 d. The behavioral changes of each group of mice were observed and recorded during the experiment, and the body weight was measured 1 d before the test（day 0）, on days 1 and 3 of the test, and on the last day of the test（day 7）, respectively. At the end of the experiment, all mice were executed, liver, muscle and all small intestine tissues were collected, tissue sections were made and H.E. staining was performed. Morphological changes of the liver and muscle were observed, and the villus height and crypt depth of the duodenum, jejunum and ileum were also measured, and ratio of villus height/to crypt depth（villus height/crypt depth） were calculated. The results showed that the overall behavioral performance of the Ganmai Dazao decoction group was better than that of the model group; the body weight of the blank group was significantly higher than that of the model group and the Ganmai Dazao decoction group on day 3 of the test（P＜0.05）, and the body weight of the blank group and the Ganmai Dazao decoction group was significantly higher than that of the model group on day 7 of the test（P＜0.05）, while the difference between the Ganmai Dazao decoction group and the blank group was not significant（P＞0.05）. The liver tissues of the mice in the blank group were normal, and the hepatocytes in the model group were necrotic over a large area with inflammatory cell infiltration; the degree of lesion in the Ganmai Dazao decoction group was significantly lighter than that in the model group. No abnormal lesions were observed in the muscle tissue of mice in each group. The difference in duodenal villus height between the groups was not significant（P＞0.05）; the duodenal crypt depth in the model group was significantly higher than that in the Ganmai Dazao decoction group and the blank group（P＜0.05）, and the value of villus height/crypt depth was significantly lower than that in the blank group and the Ganmai Dazao decoction group（P＜0.05）. The difference in jejunal villus height between the groups was not significant（P＞0.05）; the jejunal crypt depth in the model group was significantly higher than that in the blank group and the Ganmai Dazao decoction group（P＜0.05）, and the villus height/crypt depth were significantly lower than those in the blank group and the Ganmai Dazao decoction group（P＜0.05）. The values of ileal villus height and villus height/crypt depth in the model and Ganmai Dazao decoction groups were significantly lower than that in the blank group（P＜0.05）, and the difference between the model and Ganmai Dazao decoction groups was not significant（P＞0.05）, and the difference in ileal crypt depth between all groups were not significant（P＞0.05）. The results suggested that Ganmai Dazao decoction could reduce anxiety and weight loss in mice in a simulated high temperature transport model, protect liver cells and small intestinal mucosa, and could be considered as an herbal additive to prevent and treat transport stress injury.