Sushen (肅愼 su4 shen4) was an ancient ethnic group or something outside China.

The name of Sushen appeared as early as the 6th century BC in Chinese documents. They are almost unknown with the exception of the fact that they lived to the north of China and used wooden bows and crossbows. Ancient Chinese believed that the Sushen paid arrows as tribute to an ideal Chinese ruler. In other words, an arrival of Sushen delegates was an auspicious sign of the virtuous ruler for the Chinese.

From the 3rd century to the 6th century, the name Sushen was used as an alias for the Yilou (挹婁 yi4 lou2), who were in eastern Manchuria. However, the connection between the Yilou and ancient Sushen is unclear. Some historians think that Chinese, who heard the Yilou paid arrows as tributes, linked the two groups based on the knowledge of ancient documents. They paid tribute several times and pleased rulers of Northern China. The Yilou disappeared in documents in the 6th century. The Mohe rose into power there instead.

The name Sushen, which is rendered 肅愼 but pronounced Mishihase or Ashihase, can also be found in Japanese documents. According to Nihonshoki, the Mishihase first arrived to Sado province during the reign of Emperor Kimmei. In 660, Japanese General Abe no Hirafu defeated the Mishihase in Hokkaido by request from the native inhabitans. Some historians consider that the Mishihase were the same with the Sushen in Chinese records, and others think that Japanese named the indigenous people in the northeast based on the knowledge of Chinese documents, just as the Chinese did during the Three Kingdoms Period.