The amount and shape of female leucorrhea varies with the time of the menstrual cycle due to changes in the amount of female hormone secretion. Ovulation leucorrhea is clear and transparent, the amount is increased than before ovulation, and when wiped, it is easy to form as if egg-white like pulls, which is caused by the coordinated action of several hormones, easy for sperm to pass through and enter the uterine cavity and fallopian tubes, the endometrium is also easy for fertilized eggs to be laid under the influence of hormones, and sexual intercourse during ovulation is easy for pregnancy. Menstrual cycle in normal body condition, leucorrhea is paste-like, milky white, odorless, can form mucus plug in the cervix, not easy for sperm to penetrate, can block pathogens from invading the uterus, can prevent gynecological diseases. Women who are ready to have children can determine the ovulation period in general according to the shape of the leucorrhea, make physical and psychological preparations, and choose to have intercourse 4-5 days before and 3-4 days after ovulation.