. But also has close trade relations with Arab countries. In the Song Dynasty, this kind of maritime traffic further developed. China's huge merchant fleet often travels between the South Pacific and the Indian Ocean. The rapid development and expansion of maritime traffic can not be separated from the application of compass in navigation. Before the compass was used for navigation, navigation at sea could only be based on the sun, moon and stars. In case of bad weather, there is nothing to do. In the third year of Tang Wenzong (AD 838), Japanese monk Ren Yuan came to China to seek dharma. Later, he wrote the article "Journey to Seek Dharma in the Tang Dynasty", which described the chaotic and difficult scene when the sea was raining continuously: at that time, the course of the seagoing ship was beyond recognition and everyone was divided. Some say it's going north, while others say it's going northwest. Fortunately, they met a place with green waves and shallow sea, but they didn't know how far it was from the land. After the compass is used for navigation, the course can be identified regardless of cloudy weather. It was in the Northern Song Dynasty that the compass was first recorded in history books for navigation. In Zhou Pingke's Talk, Zhu Yu evaluated the prosperity of Guangzhou's shipping industry at that time, and also described the situation of China's ships sailing under threat, saying: "A sailor knows geography, but he looks at the stars at night, the sun during the day and the compass at night." At this time, the compass is only used on days when you can't see the sun, moon and stars. This is because people have more than 1000 years of experience in positioning by the sun, moon and stars, but they are not very skilled in using compasses. With the constant application of compass in maritime navigation, people's dependence on it is increasing day by day, and there are special people to take care of it. Wu in the Southern Song Dynasty said in Liang Lumeng: "When the wind and rain are dark, only following the needle board is the long palm of fire, which is unmistakable and will cover the life of a ship." From this, we can also see the position and function of compass in navigation. In the Yuan Dynasty, the compass became the most important tool for maritime navigation. Whether it is black or not, it is used to refer to navigation. Moreover, at this time, the navigation at sea has also specially formulated the compass route, where the ship went and what needle position it used, and all the routes are clearly marked. In Yuan Dynasty, there are records about compass needle in Hai Dao Jing and Da Yuan Hai Ji Yun. In the True Wax of Zhou Daguan in Yuan Dynasty, in addition to describing the experience at sea, he also wrote that the ship set sail from Wenzhou and "the trip failed". This is because the Southeast Asian countries are located in the south of China, so ships need to use the position of Ding Weizhen in the southwest when they leave Wenzhou. Zheng He, a navigator, made seven voyages to the Western Seas in the early Ming Dynasty, which expanded China's foreign trade, promoted economic and cultural exchanges between the East and the West, strengthened China's international political influence, and enhanced China's friendship with all nationalities in the world, making outstanding contributions. The safety of his large-scale voyage at sea depends on the accurate navigation of the compass. Zheng He's great ship set off from Liujiagang, Jiangsu, and went to the northern end of Sumatra Island. All the routes along the way were marked with compass needles. In the voyage after Sumatra, the compass pointer and star drawing technology complement each other. The compass provided a reliable guarantee for Zheng He to open a route from China to East Africa. The greatest influence of the Guide on the West is that the West began to explore overseas. Combined with the planned overseas exploration of the country at that time, the cooperation of astronomy, geography, shipbuilding and navigation technology, and the use of compass, a series of overseas explorations in the West were caused. Worldwide, the application of compass in navigation led to the circumnavigation of Columbus discovery of america (about 145 1- 1506) and Magellan (about 1480- 152 1). This has greatly accelerated the development of the world economy and provided an indispensable prerequisite for the development of capitalism. With the outward development of competing countries, new routes and new continents have been discovered one by one, allowing Europeans to see more different things and nationalities in a short time, and then urging Europeans to look at different nationalities and cultures with objective observation and comparison, which is another far-reaching influence of the compass.