I. Definition of infertility: China is 2 years after marriage, cohabitation, normal sexual life, without any contraceptive measures and cannot have children. WHO: After at least 12 months of normal sexual intercourse without contraception and no pregnancy. Currently, clinical infertility interventions are performed according to the WHO definition. Basic infertility assessment (mandatory for every infertility patient, 70% of the causes of infertility): semen analysis, tubal patency, ovulation. (Not as the basic content of assessment: post-coitus test; endometrial biopsy to assess luteal defect; mycoplasma culture; anti-sperm antibody test) III. If the lysis or imaging is abnormal, do hysteroscopy or laparoscopy or hysteroscopy or laparoscopy. 2, pelvic ultrasound see abnormal uterine cavity, do hysteroscopy. 3.Pelvic ultrasound for adnexal lesions (e.g. tubal effusion or tethered cyst, ovarian tumor, uterine fibroid, encapsulated effusion), laparoscopy. IV. Principles of choosing tubal examination 1. Principles: from simple to complex. lavage – imaging – laparoscopy (at least six months interval). 2.Age >35 years old-laparoscopy. 3.Suspected tubal incompetence or hydrocele-laparoscopy. 4.Suspected tuberculosis-imaging. 5.Suspected endometriosis-laparoscopy. Advantages and disadvantages of various tubal examinations 1. tubal lavage: including general lavage; lavage under ultrasound; lavage under hysteroscopy, only one hysteroscopic operation is done in each cycle, there is no need to do three or four lavages in one menstrual cycle, otherwise it is easy to be infected. 2. Hysterosalpingography, advantages: diagnosis of uterine adhesions, uterine malformations, submucosal fibroids, myometriosis, tuberculosis of the reproductive tract and tubal effusion (tubal uplift as tubal inflammation). Disadvantages: It cannot accurately reflect the degree of pelvic lesions and adhesions, cannot diagnose endometriosis, and is inappropriate to diagnose tubal passage and dysplasia. If the tubal imaging is clear, try to conceive for six months (normal sex twice a week), and if infertile, do laparoscopy. 3, laparoscopy for tubal condition, time: 3-7 days after menstruation, no intercourse. Indications: infertility older than 35 years old; tubal imaging suggestive of incompetence; ultrasound suggestive of hydrocele in the fallopian tubes; infertile for six months with patent tubal imaging; unexplained infertility.