Few today remember how far into Asia Eastern Christianity first penetrated. Several recent books should help us recall that, including:
Dietmar Winkler and Li Tang, eds., Hidden Treasures and Intercultural Encounters: Studies on East Syriac Christianity in China and Central Asia (Lit Verlag, 2009), 400pp.
The above is an edited collection featuring articles by scholars from around the world, looking at inscriptions, manuscripts, texts, and liturgy of Syriac Christianity as far into Asia as not only China but also Korea, with stops along the way in other places like Iran.
Another recent publication also travels down this Silk Road but takes a more expansive look:
Richard Folz, Religions of the Silk Road: Premodern Patterns of Globalization (Palgrave Macmillan, 2010), 208pp.
Folz looks at the variety of religious expressions found down the Silk Road, including such Eastern Christians as those once called "Nestorian."