Basal body temperature is an indirect reflection of ovarian function in women. The so-called basal body temperature is the body temperature measured after 6-8 hours of rest, before getting up, eating or talking. The basal body temperature of normal reproductive women is slightly lower after menstruation and may or may not be lower on the day of ovulation; after ovulation, the corpus luteum acts and the basal body temperature rises until the next menstruation when it falls again. The basal body temperature can be measured to understand the presence or absence of corpus luteum and the function of corpus luteum, so as to understand the presence or absence of ovulation and to estimate the date of ovulation, which is very important for the diagnosis and treatment of patients with ovarian dysfunction and infertility, as well as for the observation of the efficacy. Note: 1. Have a mercury thermometer, master the reading method and make sure it is accurate; 2. Place the thermometer next to the bed and wave the mercury column down every night before going to bed; 3. Every morning after waking up, you can measure the temperature in the mouth, which needs to be placed under the tongue for 5 minutes. If you can measure at a fixed time every morning (5:00-7:00) is better. It is strictly forbidden to get up, urinate or defecate, smoke, eat, talk, etc. before taking the temperature. If you have sexual intercourse, you should record it; 5. If you have a cold, alcohol, late sleep, insomnia, etc., which may affect your temperature, you should record it for reference; 6. If you have transient lower abdominal pain, vaginal bleeding, leucorrhoea, increased libido or other abnormalities during your cycle, you should record them; 7. Use a table, record from the left side of the table, with x indicating the beginning of the period.