Not expensive. The National Digital Library of China is composed of the ancient books library located in Jinwen Street, the south area of the main library located in Baishiqiao and the north area of the main library, forming a trinity layout. The digital library positioned as mobile reading is inexpensive and charged for personal use. However, as long as you apply for membership, you can enjoy reading and downloading e-books for free, even if you pay, it is very worthwhile.