The basic trend of the Silk Road was formed in the Han Dynasty around A.D.. It starts in the east from Chang 'an (now Xi 'an), the capital of the Western Han Dynasty, or Luoyang, the capital of the Eastern Han Dynasty, passes through Longxi or Guyuan westbound to Jincheng (now Lanzhou), then passes through Wuwei, Zhangye, Jiuquan and Dunhuang counties in the Hexi Corridor, exits Yumenguan or Yangguan, and passes through Bailongdui to Loulan in Lop Nur. In the Han Dynasty, the western regions were divided into south roads and north roads, and the bifurcation point of the two roads was in Loulan. Northbound, passing through Quli (now Korla), Qiuci (now Kuqa) and Gumo (now Aksu) to Shule (now Kashgar). South Road starts from Shanshan (now Ruoqiang), passes through Qiemo, Jingjue (now Minfeng Niya Site), Khotan (now Hotan), Pishan and shache to Shule. From Shule to the west, across Congling (now Pamir) to Dawan (now Fergana). From here, we can go west to Daxia (in present Afghanistan), Sogdian (in present Uzbekistan) and Rest in Peace (in present Iran), and as far as the plowshare in Daqin (in the eastern part of the Roman Empire) (also known as Li Xuan, in Alexandria, Egypt). The other road is from Pishan southwest, crossing the crossing (now Darier, Pakistan), passing through Kebin (now Kabul, Afghanistan) and Wuyishan (now Sistan), and heading southwest to Tiaozhi (now at the head of the Persian Gulf). If you travel south from Bin to the mouth of India (now Karachi, Pakistan), you can also reach Persia and Rome by sea. This is the basic trunk road of the Silk Road formed after Zhang Qian made two missions to the Western Regions during the reign of Emperor Wu of the Han Dynasty. In other words, the Silk Road in a narrow sense refers to the above-mentioned road.

The Silk Road in history is not static. With the change of geographical environment and the evolution of political and religious situation, some new roads have been opened, and some roads have changed or even been abandoned. For example, Bailongdui between Dunhuang and Lop Nur is an Yadan terrain that often disorients travelers. When the Northern Xiongnu on the Mongolian Plateau was defeated in the early years of the Eastern Han Dynasty, it was forced to move westward. After the Central Plains dynasty firmly occupied Yiwu (now Hami), it opened the "Northern New Road" from Dunhuang to Yiwu. From Yiwu via Gaochang (now Turpan) and Yanqi to Qiuci, it meets the original Silk Road North Road. During the Southern and Northern Dynasties, the north and south of China were in opposition, while the east and west of the north were also in harmony. Under such circumstances, the communication between the Southern Dynasties, the Song Dynasty, the Qi Dynasty, the Liang Dynasty, the Chen Dynasty and the Western Regions was mostly along the Yangtze River to Yizhou (now Chengdu), and then to Longhe (now Songpan) in the north, passing through Tuguhun Capital on the shore of Qinghai Lake, and passing through the Qaidam Basin in the west to Dunhuang, which merged with the Silk Road trunk road. Or cross the mouth of Altun Mountain to the west, enter the Shanshan area of the western regions, and merge with the south road of Silk Road. This road is called "Tugu Hundao" or "Henan Road", and today people also call it "Qinghai Road". And from the north of the Central Plains or Hexi Corridor to the Mongolian Plateau, then westward to the northern foot of Tianshan Mountain, across the Ili River to the broken leaves (now near tokmak), and into Central Asia. This road was later called "Beixin Road", which flourished during the Mongol Khanate and the Yuan Dynasty.

In addition to the overland Silk Road, China people started to open a waterway from Guangdong to India from the Han Dynasty. After the Song Dynasty, with the further development of southern China and the shift of the economic center of gravity to the south, the sea routes from Guangzhou, Quanzhou, Hangzhou and other places became increasingly developed, going further and further, from Nanyang to the Arabian Sea and even as far as the east coast of Africa. People call these maritime trade routes "Maritime Silk Road".