Abstract： Prof. YOU Zhaoling proposed the concepts of endometrial low reactivity and abnormality of endometriummyometrium junctional zone for thin endometrium ， and believed that the abnormality of endometrium-myometrium junctional zone is closely correlated with the occurrence of thin endometrium and low reactivity in Chinese and western medicine treatments. The authors summarized the clinical experience of Prof. YOU Zhaoling，and pointed out the key role of abnormal junctional zone in the diagnosis and treatment of thin endometrium and the terminal of reproductive chain under the auxiliary diagnosis of the four-dimensional vaginal color ultrasound. We also proposed the understanding and strategy of the diagnosis and treatment of abnormal uterine junctional zone in Chinese medicine.