As a physiological barrier for restricting material exchange between blood and brain, blood brain barrier prevents harmful substances from entering the brain and maintains the stability of the central nervous system. In recent years, researches on the structure and function of the blood brain barrier among different species has progressed largely, which help to reveal the evolution of the blood brain barrier and to understand the specific mechanism regulating. This article will review the structure and function of the blood brain barrier of multiple animals including fish, birds, and mammals in recent studies.