Abstract: Rare and endangered animals(REAs), as a focal point of current research, play a vital role not only in maintaining ecosystem services and functions but also in delivering significant value to human societies. This paper reviews the research progress on the ecological value of endangered and rare animals, systematically tracing the evolution of its research history, definitions and classifications, and developing a comprehensive classification framework to illustrate the multidimensional attributes of their ecological value. Furthermore, the article summarizes key findings in the field of value assessment, highlighting the limitations of existing research, which tends to focus disproportionately on the use value of large, charismatic species while neglecting other taxa. In terms of non-use value, studies indicate that its magnitude is significantly influenced by human social characteristics (e.g., cultural background and economic status) and animal-specific traits (e.g., aesthetic appeal and degree of endangerment). Additionally, the paper reviews commonly employed methodologies, including interdisciplinary approaches integrating economics, sociology, and ecology, offering methodological guidance for future research. Current value assessments remain incomplete, underscoring the need to expand the scope of evaluation, balance the emphasis on use and non-use values, and provide robust support for ecological conservation and sustainable development policies.