Basal body temperature (BBT) refers to the temperature measured during a long period of sleep (6-8 hours), after waking up and not yet up and active, reflecting the energy metabolism level of the resting state of the body, so it is also known as resting body temperature. Can indirectly reflect the ovarian function, in the menstrual cycle, with different periods of estrogen and progesterone secretion of different amounts, basal body temperature cyclical changes. Development of mature women’s basal body temperature, in the first half of the menstrual cycle is slightly lower, generally between 36,3 ℃ ~ 36,5 ℃, the lowest ovulation, ovulation, due to the warming effect of progesterone, can make the basal body temperature higher than the ovulation of 0,3 ℃ to 0,5 ℃, to the menstruation of 1 to 2 days before the menstruation or menstruation on the first day of the decline. Therefore, the normal menstrual cycle basal body temperature is a biphasic curve. The anovulatory menstrual cycle lacks progesterone, the basal body temperature does not have the above regular cycle fluctuations, so it is a monophasic curve. 1, the method of patients to determine their own, every night before going to bed will be the thermometer mercury column flung to 35 ℃ below, and will be placed on the bedside table or pillow side, reach out that can be taken place. The second morning after waking up, do not speak, do not get up, do not move, first take the thermometer placed under the tongue, oral temperature measurement for 5 minutes. It is best to fix the time of measurement every day, generally in the morning 5 ~ 7 o’clock, night shift workers should be in the rest 6 ~ 8 hours, just woke up when measured. The temperature measured every day should be recorded on the basal body temperature list, and finally plotted as a curve, and relevant situations in life such as sex life, menstruation, insomnia, colds, etc., as well as the treatment given should be recorded on the basal body temperature list at any time, so that it can be used for reference at any time. Generally, it should be measured continuously for at least 3 menstrual cycles. 2, the clinical application of basal body temperature measurement method is simple and easy to implement, without any damage, can be measured by the patient, through the observation of basal body temperature, can understand the patient with or without ovulation and luteal function, so the basal body temperature measurement is clinically used to understand the function of the ovary is most commonly used as an auxiliary examination method.