It is generally accepted that precocious heart disease is the result of the interaction of genetic and environmental factors, and that the etiology and environmental risk factors differ for different types of precocious heart disease. Genetic factors include: (1) A tendency for some degree of familial morbidity. (2) Multiple genes interacting with environmental factors. (3) Monogenic disorders. (4) Chromosomal disorders. Environmental factors include: (1) viral or bacterial infections (cytomegalovirus, toxoplasmosis, rubella virus, coxsackievirus), colds, fever in the first trimester of pregnancy. (2) Lesions of the amniotic membrane, fetal compression, preterm abortion in early pregnancy. (3) Maternal: malnutrition, diabetes mellitus, phenylketonuria, hypercalcemia, early miscarriage, history of preterm abortion, mental stimulation during pregnancy. (4) Maternal regeneration, excessive age, smoking. (5) Radiation. (6) Use of drugs in early pregnancy: aspirin; tetracyclines; contraceptives, fertility drugs, progesterone, exogenous estrogens; antiepileptic and anticonvulsant drugs; lithium; sedative and antiemetic drugs; tribromine tablets; perforator; furantadine; sulfonamides; viralin; dysentery; ethanol. (7) Chemical poisons: contact with chemicals such as dye, paint, printing, benzene, carbon disulfide, pesticides, ammonia, xylene, gasoline, lead, plastic, etc. (8) Alcohol and tobacco use by father, older father; history of secondary chronic diseases such as diabetes, hypertension, epilepsy, and phenylketonuria. (9) Parents’ lifestyle habits and health awareness: premarital checkups, gynecological examinations, knowledge of weeks of pregnancy, etc. (10) Altitude of birthplace: higher incidence in highland areas than in plain areas.