Abstract: ［Purpose/Significance］This paper aims to study and draw on the experience of the British Library in order to promote China’sdata opening process in libraries. ［Design/Methodology］This paper analyzes the conversion of resources into open data in the British Library from legal and technical aspects, and also investigates their promotion of data reuse. ［Findings/Conclusion］In legal aspect, the British Library adopts different opening and licensing strategies for public domain works, orphan works, works of self-owned copyright, and works involving the copyrights of others. The British Library opens data to the public domain in the premise of legality. From the technical aspect, the British Library focuses on improving the discoverability, accessibility and analyzability of data. In the promoting measures of data value creation, the British Library actively adapts to users and  innovate data usage approaches. According to the situation in China, this paper provides some suggestions on data opening in libraries, including unconstrained use of digital copies of works in public domain，integration of data into the Internet environment, and encouragement of users’ participation in data opening practice. ［Originality/Value］This paper provides reference to libraries’open data practice, and enhances the value of library data in China.

Key words: Data opening, The British library, Public domain works, Digitalization, Data reuse