Abstract: The promulgation of the Public Library Law not only makes it possible for social forces to establish private libraries, but also legitimizes the latter. The establishment of private libraries has played a very important role in safeguarding the basic rights of citizens and promoting the sustainable development of the public library cause. However, the Public Library Law is not strong enough to regulate private libraries, and it is not specifically targeting at private library, making it difficult to effectively regulate and promote the development of private libraries. Therefore, Public Library Law should be amended to make a careful regulation on the basic principles, the main body, conditions and procedures, operation mechanism, support and guarantee, supervision and inspection, withdrawal and takeover of private libraries, so as to lay a legal foundation for the sustainable development of private libraries in China.