Based on the technique of infrared information, we improved the experimental method and displayed the meridian courses over the body surface successfully. Observation of the meridians on the back was performed on 23 healthy adults in this work, and 164 lines of infrared radiant track have been recorded. About 40% of them travelled through the back from lumbus to neck and their courses coincided or basically coincided with Du meridian and Urinary-Bladder meridian in that region. Several meridian courses could be displayed simultaneously in the observation. Symmetry was one of the important characters of the infrared radiant track on back region and it appeared alone in one side only in occasional case. The intensity of infrared radiation was the highest in Du meridian, the medial line of Urinary-Bladder meridian in second and the lateral line of Urinary-Bladder meridian was the lowest. Since there are no large blood vessels in longitudinal direction in the subcutaneous tissue of this region, therefore, the radiant track recorded obviously bared no relation to the large blood vessels. The above results demonstrated that the courses of Du meridian and Urinary-Bladder meridian were inherent in human body and could be displayed objectively.