With the purpose to clarify the deposited region of bilirubin and the cause of green tone in the skin of jaundiced patients, the author made the histochemical observation, employing the frezing-drying and also made the observation on the stainability of both fibers, being chiefly composed by collagen and elastoid, to the serum of jaundiced patient and various bilibubin solutions in vitro, using the tail's tendon of young white rat. And the results were as follows. 1. The author applied the freezing-drying to the histochemical studies on the skin stained by bilirubin and got the satisfactory results. 2. As for the staining condition of bilirubin in the skin of jaundiced patient, it was diffuse, but not the paticular region or fiber. 3. Staining the fiber, being chiefly composed by collagen and elastoid, by each solution of cristallin bilirubin, bilirubin soda salt, natural salt-form and ester-form bilirubin and serum of jaundiced patients in the buffer solutions with various pH value, the stainability was the best on the use of ester-form bilirubin and the best pH value was 7.0, and the deposited bilurbin was easily changed to biliverdin on the shift of pH to alkaline side. 4. Staining the above both fibers by biliverdin as same as bilirubin, it's staining deposition was the same degree with that of bilirubin. 5. Therefore, the staining deposition of skin in jaundice was not in the elastin of elastic fiber as put forward by F. Rosenthal, it was diffusely seen in the whole of skin and it was rather strong in the collagenous fiber than elastoid. Shifting the pH of skin to akaline side, the deposited bilirubin was easlly changed to biliverdin and Verdinikterus was occured from it.