In the decades of clinical treatment of infertility, professor YOU Zhao-ling has formed a unique ‘diseases, syndromes, stages and time' diagnosis model with time and space characteristics. In this paper, the formation of origin and spatialtemporal characteristics of this model was elucidated, and rich clinical experience of professor YOU was summarized. Professor YOU took dif erentiation of disease with western medicine as the outline and the TCM dif erentiation with synthesis of the four diagnostic methods as the detailed regulations when di...