Ubiquitous knowledge environment with five salient features is transferring from concept to reality. The library based on ubiquitous knowledge environment not only faces the rare development opportunities with three levels, but also encounters unprecedented challenges and crises. Building a system with characteristics of high-quality mass knowledge resources, creating a personalized intelligent service system and establishing human values, achieving transfer from the information services to knowledge services, and constructing a highly collaborative library alliance are the only ways for the healthy development of Chinese libraries under ubiquitous knowledge environment.