I. Introduction:

? The Silk Road is a transportation network consisting of land routes and settlements, extending from the South China Sea coast to the Mediterranean Sea and the Indian subcontinent. For nearly two thousand years, it is not only an important channel for the exchange of ideas and commodities, but also represents the history and culture of different societies. This era is also an era to commemorate the social and cultural exchanges between the East and the West.

? It is a complex transportation system, which was developed entirely for utilitarian purposes and does not need to be named. It was not until 1877 that this route was built by Ferdinand, a European scholar and explorer working in Turkey at that time. Feng? Richthofen was named "Silk Road" and is widely known. Although the name is romantic and lyrical, it is misleading. There is no doubt that China's silk is one of the most important commodities exported from the East to the West, but other kinds of commodities are traded on this trade road, including precious metals and gems, porcelain, perfume, paper, decorations and spices, as well as cotton, textiles, glass, red wine, amber, carpets and so on, which are transported from the East to the Mediterranean. In addition, there are excellent horses produced in Fergana Valley in Central Asia, which are sold to the east and west along this route.

? Not only did goods circulate along the Silk Road, but Buddhism also spread from India to Japan in the east and Turkmenistan in the west through the Silk Road. Through the Silk Road, Judaism, Islam and Christianity were introduced into China from the Mediterranean, Zoroastrianism and Manichaeism. In addition, scientific and technological achievements also spread through the Silk Road: China's papermaking, printing, gunpowder, iron smelting, crossbows, compasses and porcelain were introduced to the west, while western engineering technology (especially bridge building), cotton planting and processing, brocade weaving, astronomical calendar, grape planting and glass and metal processing technology were introduced to the East. In addition, the exchange and dissemination of medical knowledge and technology, fruits and grains are also very frequent. According to historical records, ancient ruins, archaeological sites and route composition, it can be inferred that the essential feature of the Silk Road is the main channel for transnational exchanges of goods, population and ideas.

Second, the geographical characteristics:

? At present, it is generally believed that the eastern starting point of the Silk Road is Chang 'an (Xi 'an today), and then Luoyang was added. In the early days, the Silk Road began in the west of Xi, and then divided into several main routes leading to northwest Asia, southeast Asia and south Asia. Among them, the sea route has developed into an evolutionary "Silk Road". According to the research of historical documents, the main routes are desert route, grassland route, sea route and Buddhist route. The Buddhist route from northwest and southwest of China to Central Asia and South Asia has aroused widespread concern.

From east to west, the Silk Road crosses the fertile Central Plains of China, crosses the Hexi Corridor of Gansu and reaches the north and south of Tianshan Mountain. Its southern line divides into two branches here, and meets in Kashgar after crossing the Taklimakan desert. The southern line of the Silk Road starts from Kashgar, passes through the Karakorum Mountains to northern India, and one of its branches passes through the Pamirs to south-central Tajikistan. The central line crosses the Pamirs to Bourcq, passes through Melv to Iran, and passes through Kabul to India. The northern line runs through Fergana Valley to Samarkand, where a northbound road runs through the Amu Darya River basin between Aral Sea and Caspian Sea, and finally reaches the ports along the Black Sea. In addition, from Samarkand, cross the Central Asian prairie and go south to Melv. Teheran can be reached from Murf, Mesopotamian plain passes through Taixi Peak, or ports along the Mediterranean coast pass through the ancient city of palmira.

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In addition, there are several important routes across the mountains to the Indian subcontinent, which are also part of the Silk Road transportation network. The westernmost of these routes passes through Bulko, passes through the Hindu Kush Mountains to reach today's Afghanistan, passes through Kabul to Pakistan, and enters the Indian alluvial plain through Tahira. In addition, some feeder lines are connected with the trunk lines located in Caucasus countries and Israel.