I. What is hysteroscopy? Hysteroscopy is a new, minimally invasive gynecologic treatment technique for the diagnosis, treatment, and follow-up of lesions in the uterine cavity. II. What are the indications for hysteroscopy? 1, all kinds of abnormal uterine bleeding, including: excessive menstruation, frequent menstruation, irregular excessive uterine bleeding, irregular uterine bleeding, postmenopausal bleeding, scanty menstruation, scanty menstruation; 2, occupying lesions in the cervical canal and uterine cavity 3, abnormal intrauterine device and intrauterine foreign body. 4, infertility and sterility (uterine cavity and fallopian tubes) 5, residual uterine cavity, uterine pregnancy without residue, etc. 6, uterine cavity and cervical adhesions 7, uterine malformation 8, abnormal uterine cavity imaging 9, vaginal drainage and/or foreign body in the vagina of young girls 10.Assessment related to post-operative hysteroscopy 11.Pre-operative lesion scope observation and microscopic biopsy taking for endometrial and cervical canal cancer