The present article reveals the mistake Mr. Li Yuan-hsing(李元星) made in his article "The Earliest Date Traceable of the Main Source of the Yellow River". Mr. Li based his article on the map drawn by Yang Tze Ch'i(杨子器) of the Ming Dynasty. On that map, one can find below the Starry Sea(星宿海)two riveilets which Mr. Li ratiocinated to be the Yo Ku Tsung Lieh Chu (river)(约古宗列渠)—the main source of the Yellow River and its branches. Iie further inferred that the Yo Ku Tsung Lieh Chn was found, as oarly as the T'ang and Yuan Dynasties, to be the main source of the Yellow River.