(1) Background: Japanese Kampo medicine has its origin in ancient Chinese medicine. In 742, a Tang Dynasty monk named Jianzhen (Ganjin) was invited by Japanese clerics to visit Japan and teach commandments in Buddhism. Because of the dangers of the voyage and also other obstacles, he took 11 years to reach Japan on the sixth voyage and he was blind when he arrived in Japan. He was the first person in China to go to Japan to establish the Buddhism commandments, and he was also the first person in Japan to directly teach traditional Chinese medicine. Until now, there have been few reports in English about the details of the Chinese herbal medicines he brought to Japan, including the types of herbal medicines, pharmacological activities, and formulations. In the review, we systematically and comprehensively summarized Jianzhen’s life from the standpoint of his medical and pharmaceutical knowledge and the types and pharmacological activities of Chinese herbal medicines and prescriptions that were brought to Japan by Jianzhen; <br> (2) Methods: A review was made on the relevant literature written by Chinese, Japanese, and English languages regarding the medical and pharmacological knowledge of Jianzhen, the 36 Chinese herbal medicines brought to Japan by Jianzhen, and the pharmacological and therapeutic effects of these 36 herbal medicines, as well as their formulations; <br> (3) Results: The review of the literature proved that Jianzhen’s prescriptions served as a basis for current herbal medicines (Kampo) in Japan. In the process of the literature search, we found a book entitled Jianshangren (Holy Priest Jianzhen)’s Secret Prescription, which recorded the complete prescription of the 36 traditional Chinese medicines Jianzhen brought to Japan; <br> (4) Conclusions: Jianzhen is one of the ancestors of traditional Chinese medicine/Kampo medicine, and he brought traditional Chinese medicine and medical books to Japan for patients. He made important contributions to the development of traditional Chinese medicine in Japan.