Neural tube defects(NTDs) are common congenital malformations that are caused by an improper neural tube closure during embryonic early development.Neural Tube Defects are likely to result from genetic and environmental factors.Now,investigation is the focus on the relationship between factors that are related to the homocysteine metabolic and risk of neural tube defects. This paper reviews the key enzymic and important factors genes involved in the homocysteine metabolic and the relationship between the genetic polymorphism on specific sites and risk of neural tube defects.