The Chinese University of Hong Kong Library (CUHK Library) collects about 1,100 titles of Chinese rare books and over 6,000 titles of Chinese semi-rare books. Since this collection is one of the major collections of its kind in Hong Kong, CUHK Library has started to digitize selected titles from the Yuan Dynasty onwards in 2006 to build up this Chinese Rare Book Digital Collection, in order to facilitate online access of its full- text and to promote resource-sharing. To extend our support to learning and global research, the Collection is also the first open access digital collection of the CUHK Library and has been harvested into several well-known OA repositories such as OpenDOAR (Directory of Open Access Repositories), Registry of Open Access Repositories (ROAR), OCLC WorldCat OAIster, Open Archives Initiative, and BASE. The Collection now covers more than 6,200 volumes of rare books with around a million of full-text images and the number is still growing.