Because at that time, the monks in Jian Zhen brought many advanced Buddhism and the original works of the eminent monks in the Tang Dynasty to Japan. Although it greatly promoted the Japanese Buddhist culture at that time, it also made China lose those precious cultural relics. So this is the place that was criticized and rejected by later generations. But there was no such concept of cultural treasure at that time. It turns out that so many monks have not survived. So it gradually disappeared.

Mainly because China at that time had become the center of Buddhist culture. So at that time, China was a very powerful country, which had a great influence on neighboring countries and regions. Therefore, with the national strength of China at that time, Buddhist culture gradually spread outward. One of the main ways for Buddhism and Buddhism to spread to the east is to spread to Japan through the Korean Peninsula. As early as the Southern and Northern Dynasties to the Sui Dynasty, monks from Silla (located in present-day Korean Peninsula) came to China to seek dharma. Of course, some of them went directly to India to study, but later they spread Buddhism, which can be said to be mainly from China.

However, at that time, it was clear to us that Buddhist culture was still a foreign culture when Jian Zhen monks travelled eastward. It also caused the division of the Japanese imperial nobles. Supporters and opponents held their own words, even the imperial edict promulgated by the emperor was repeated several times, and then Buddhism was lifted, showing its contradictory mentality. It was not until Shoto Kutaishi came to power that this problem was completely solved. He encouraged the study of Buddhism, combining Japanese native beliefs, Confucianism and Buddhism. Since then, Japanese Buddhism has embarked on the road of prosperity. So Jian Zhen monks played a very important role.

Of course, this was also related to the large-scale Buddhist extermination movement in China at that time, so in order to preserve the foundation of Buddhist culture and spread it to the outside world. This is why monks in Jian Zhen choose to travel to Japan. Out of a strong sense of hardship, some eminent monks hope to open up new Buddhist land and preserve more Buddhist seeds in the world around them. At that time, Buddhism was in the ascendant in Japan, which was undoubtedly the best choice. Therefore, they began to travel to Japan very early, and the most representative figure was monk Jian Zhen, who had visited Japan six times at the request of Japanese monks studying abroad.