Infertility: defined as one year without any contraception and normal sexual intercourse without successful pregnancy. It is mainly divided into primary infertility and secondary infertility. Primary infertility is defined as never having conceived; secondary infertility is defined as having been pregnant and then being infertile. According to this strict definition, infertility is a common problem that affects approximately at least 10-15% of couples of reproductive age. The causes of the onset of infertility are divided into male infertility and female infertility. I. Male partner: The best time to check semen is 3-7 days without semen emission and no recent alcohol consumption, exertion, smoking, etc. 2. Female side: basic examination: gynecological examination, transvaginal ultrasound, female endocrine, full set of vaginal and cervical secretions; additional examination: hysterosalpingography; hysteroscopy; laparoscopy 1. For those who have regular menstrual cycle (i.e. one cycle of about 30 days), it is recommended to come to the hospital on the 8th-10th day of menstruation to monitor the follicles. It is recommended to come to the hospital to monitor the follicles from the 8th to the 4th day of menstruation. 2. For those who have irregular menstrual cycle (i.e. menstrual cycle is too short below 25 days or prolonged above 35 days), it is recommended to come to the hospital for endocrine examination and ultrasound examination on an empty stomach on the 2nd-3rd day of menstrual bleeding or before 9:00 am on the 21st day. 3. Tubal lavage or imaging: for those with previous history of miscarriage and uterine operation. Normal menstruation completely clean for 2-5 days, no intercourse, no recent cold and fever to the hospital. 4.Hysteroscopy and lavage: for suspected uterine adhesions after IUD removal, embryonic abortion or unexplained significant decrease in menstrual flow; local inspection and imaging for tubal obstruction or incomplete obstruction; endometrial polyps; multiple spontaneous abortions, etc. Normal menstruation completely clean for 2-5 days, no intercourse, no recent cold and fever to the hospital. Note for first consultation or visit to the hospital: 1. Please explain the necessary information including: male semen examination; female menstrual status; whether the fallopian tubes are examined or the results of the examination; past pregnancy and delivery history; 2. Please bring all previous examination reports, especially the imaging film and report, female endocrine examination and male semen examination report.