Almost 100 years after Xuanzang returned to Chang'an, Jianzhen, another eminent Buddhist monk of Tang Dynasty, crossed the ocean eastward to Japan, to spread Buddhism.

Jianzhen was born in Yangzhou. As the abbot of Daming Temple in that city, he received envoys sent by the ruler of Japan in 742, who requested that teachers of Buddhism be sent to their homeland. Jianzhen decided to go by himself. However, the crossing was fraught with hazards, yet he said deceivably: "How can i give up my faith in order to protect my body?" It was only on his sixth attempt that Jianzhen arrived in Japan. At that time, he was already 66 years old, and blind. He, with his 23 disciples had brought a great amount of books, the image of Buddhism, Buddhistic scripture, and some other treasure.

Jianzhen lived in Japan for 10 years. He not only spread knowledge of Buddhism, he also made prominent contributions to Japanese architecture, medicine and art. He designed Toshodai Temple in Nara, which was treasured as a "Bright Pearl". He had also exerted great influence on Japanese medicine; he was praised as the Founder of Medicine. Jianzhen died in Japan.