到了元代大德年间，王桢发明了用木活字印书，可惜这些都没有传本，国内现存最早的活字印刷实物是国家图书馆藏元朝的《御试策》。
of which none has come down to the present day . The oldest moveable-type printed book in existence in China is Yushice in the Yuan Dynasty , which is now collected in the National Library of China .
王桢