Where are Nestorian Christians today?

The  Nestorian Church had a presence in China during two periods:

 first from the 7th through the 10th century
 Later during the Mongol Yuan Dynasty in the 13th and 14th centuries

Today the Assyrian Church has around 170,000 members, and they are located mainly in Iran, Iraq, and Syria.

This is a picture of a Nestorian Church in Baghdad.

The Christology of the Church of the East has its roots in the Antiochene theological tradition, which was of the early Church.