||OBJECTIVE: By observing body surface temperature variation of the intermediate structures of the Lung (Fei) and Large Intestine (Dachang) exterior-interior relationship in asthmatic patients, to investigate the pathological response on the pathway of channels and to substantiate the objective existence of the intermediary structures. METHODS: The study included 60 subjects meeting the bronchial asthma inclusion criteria (experimental group) and 60 healthy subjects (normal control group). ATIR-M301 infrared thermal imaging device was used for detecting body surface temperature of the subjects and collecting the infrared thermal images. The temperature values of the intermediate structures of Lung and Large Intestine exterior-interior relationship [throat, Quepen, elbow, nose, Lieque (LU 7), Pianli (LI 6)], control areas (0.2 cm lateral to the above structures) and Yintang (EX-HN 3) were measured on the infrared thermal image by infrared imaging system. Then, the above temperature values were compared and analyzed within and between two groups. RESULTS: There were insignificant differences between the temperature on the left and right sides of the intermediate structures (Quepen, elbow, LU 7, LI 6) in normal control group (P>0.05). Except for that of Quepen, there were insignifificant differences between the temperature of the intermediate structures and their corresponding control areas in normal control group (P>0.05). In the experimental group, the temperature on the left and right sides of the intermediate structures (Quepen, elbow, LU 7, LI 6) showed statistically signifificant differences (P<0.05 or P<0.01); the temperature difference between intermediate structure (throat, Quepen, elbow, nose, LI 6) and their respective control areas were also significant (P<0.05 or P<0.01). The temperature of the intermediate structures (throat, Quepen, elbow, LU7, LI 6) between the experimental group and normal control group showed signifificant differences (P<0.05 or P<0.01). CONCLUSIONS: This study is an initial step to validate the objective existence of Lung and Large Intestine exterior-interior relationship intermediate structures, as described in the Chinese classical medical literatures, through the functional imaging angle. The intermediate structures are the pathological reaction areas of the bronchial asthmatic patients.