The author has seen many male patients in their 30s and 40s in the clinic, complaining of low libido and lack of interest in sex life, what causes low libido? The cause of low libido in men is divided into organic and functional, many diseases and drugs have a suppressive effect on libido, but more commonly caused by psychological and social factors. The common causes are: 1, suffering from acute and chronic diseases, such as endocrine diseases, tumors, blood diseases, tuberculosis, diabetes, severe anemia, liver and kidney diseases, etc. 2, such as medication, it has been confirmed that some drugs can be caused by low libido, such as blood pressure drugs Risperdal, diuretics Ativan, cardiovascular drugs Coronarin, Colistin, and other methyldopa, estrogen, ethanol, phenytoin sodium, etc.. 3, psychological factors and physical weakness is the most common cause of low libido, common triggering factors are traditional concepts, wrong sexual knowledge, superstitious religion, failure of the first sexual intercourse, sexual life trauma, marital failure, low self-esteem, husband and wife emotional discord, physical incompetence, work overwork, etc.. The necessary treatment should be carried out according to the different causes in order to be effective.