Abstract:There were some disputes about the concept and mechanism of biological evolution. This paper tried to give more explanations on the key concepts. The biological adaptability was distinguished into two different concepts: bio-logical evolution and specialization. The former was defined as the process of biologically gradual evolvement, and the latter was considered as the process of species formation at horizontal development. Moreover, a new concep-tual framework was applied to the popular biological theories known by people, and the previous research results or discoveries were explained over again.