The Maritime Silk Road was formed during the reign of Emperor Wu of the Han Dynasty. The South China Sea route from China to the west is the main line of the Maritime Silk Road. At the same time, there is the East China Sea route from China to the Korean Peninsula and the Japanese islands, which plays a secondary role in the maritime Silk Road. As for the South China Sea route of the Silk Road in the Han Dynasty, the Book of Han · Geography records the voyage of the envoys sent by Emperor Wudi of the Han Dynasty and enlisted merchants. It says that they set sail from Rinan (today's central Vietnam) or Xuwen (today's Guangdong) and Hepu (today's Guangxi) along the east coast of Indochina Peninsula and arrived at Duyuan (today's Dishi in southern Vietnam) in the Mekong Delta after five months. After a four-month voyage north along the west coast of Indochina Peninsula, we arrived at Yilu (today's Buddhist Series in Thailand) at the mouth of the Chao Phraya River. From then on, the south along the east coast of the Malay Peninsula, after more than 20 days arrived in Cham (now Thailand's Bashu), here abandoned ship landing, cross the isthmus, walk more than 10 days, arrived in the capital of Lu (now Burma's Danna Sarin). Then he boarded the ship and sailed west to the Indian Ocean, where he reached the Yellow Branch (now Conchpuram on the southeast coast of India) in more than two months. On his way home, he sailed south from the Yellow Branch to the Kingdom of Bucheng (present day Sri Lanka) and then sailed directly east. After eight months, he arrived at the Strait of Malacca and landed at Piczon (present day Piczon Island, west of Singapore). Finally, he sailed for more than two months from Piczon to Xianglin County, Rinan County (present day Chah Sagewheat, south of Vichuan County, Vietnam).
