This presentation explores how the Maritime Silk Road was used to interconnect ancient nations by focusing on the exchange of glass. We argue that a close look into the exchange of glass can provide a precise understanding of how and when international relations were made. This presentation is divided into two parts. The first part looks into how glass ware was exchanged from the east to the west along the Maritime Silk Road, which covers and connects a wide geographic area including the Mediterranean Sea, the Red Sea, the Arabian Sea, the Bay of Bengal, the South China Sea, the Yellow Sea and the East Sea. Among the materials that were exchanged, glass ware was important, namely Roman glass, Sasan glass, and Islamic glass. This part explores how Roman glass was distributed through Rome and the Mediterranean, the site of Arikamedu, which was the largest trading hub in India, and through to Hepu in Southern China. It also briefly examines how Sasan glass played a role in the Sasan dynasty and how Islamic glass was produced and distributed in relation to the countries that passed by the sea. The second part focuses on glass beads which were widely distributed in the Indian and Pacific Oceans. It refers to results gained from chemical composition to trace how, from the 2nd century BC to the 6th century AD, there was a change from potash glass to high alumina soda glass throughout the inland parts of Southeast Asia, southern China, the Korean peninsula, and the Japanese archipelago. What this shows is the chain reaction of changes in Southeast Asia and how the Korean peninsula was interconnected to Southeast Asia, Funan in particular, via the Maritime Silk Road. The study of glass can shed light on ancient exchange.