1. Classification according to the history of infertility: it can be divided into primary infertility and secondary infertility. The former refers to the marriage has never had children, the latter refers to have had one or several births, and then more than a year, no contraceptive measures, but still no child; 2, according to the possibility of treatment classification: can be divided into absolute sterility and relative sterility. Infertility without hope of successful treatment is called absolute infertility, and infertility with hope of successful treatment is called relative infertility; 3, according to the nature of the etiology of the classification: can be divided into sexual infertility and pathologic infertility, qualitative infertility and functional infertility, congenital infertility and congenital infertility; 4, according to the etiology of the cause of infertility: according to the interference with the different aspects of the reproductive process of sexual infertility and semen test of the abnormal state of sexual infertility.