The easiest and most effective way to check for luteal insufficiency is to measure the basal body temperature. Luteal function can be inferred from the length of the luteal phase, the magnitude of the rise in temperature and the time of the fall. The luteal phase is calculated from the first day of rise after the fall in body temperature during ovulation, the number of days of normal luteal phase should be 12-16 days, such as less than 12 days is one of the evidence of luteal insufficiency. In addition, if the luteal phase temperature rises, but the rise is less than 0.5℃ or slower, the phenomenon of climbing, or falls earlier, the luteal phase temperature fluctuates greatly, are signs of insufficient luteal function, should be measured continuously for 3 months to avoid errors. Secondly, the level of sex hormones in the blood should be tested, or the endometrium should be taken within 12 hours of menstruation for examination, and if the pathological examination shows poor secretion, it can also be used as a diagnostic reference. Luteinizing insufficiency refers to menstrual disorders, early miscarriage and infertility caused by insufficient secretion of progesterone from the ovarian corpus luteum. The cause of luteal insufficiency is not fully understood, but it may be due to imbalance of follicle growth hormone and luteinizing growth hormone secretion, resulting in follicular dysplasia and defective corpus luteum formation, and thus insufficient progesterone secretion from the corpus luteum after ovulation. Endometriosis and increased prostaglandin release from the endometrium after miscarriage can also affect luteal function. Luteinizing insufficiency can also occur after unreasonable use of clozapine and progesterone therapy. In addition, hyperprolactin often occurs in conjunction with luteal insufficiency. The diagnosis of luteal insufficiency can be based on basal body temperature, blood progesterone measurement and endometrial biopsy. In these patients, basal body temperature is biphasic, but rises and falls slowly, with a rise of less than 0.3°C, and lasts only 9-10 days, sometimes with an extended follicular phase. On the 8th day of basal temperature rise, blood progesterone is less than 10 mcg/mL. In the past, the diagnosis was generally based on endometrial biopsy on day 21-22 of menstruation and the endometrial phase was less than normal for more than 2 days. Nowadays, it is found that some patients with clinical diagnosis of luteal insufficiency are suffering from unruptured follicular syndrome by laparoscopy. Therefore, the diagnosis of this disease should also be confirmed with ultrasound and laparoscopy.