Down Syndrome (DS) is the most common cause of mental retardation with incidence of 1 in 848 (Lin, Hu et al. 1991). Although prenatal Down syndrome and Amniocentesis had been applied for years, in the survey of 2005, current birth incidence of DS is 1.6 in 10,000 live birth, meaning a 30-50 new cases per year (Jou, Kuo et al. 2005). Patients with DS will have multisystemic manifestations including short stature, mental retardation, dysmorphism, congenital heart disease, congenital anomaly of gastrointestinal and genitourinary tract, abnormal endocrine function, leukemia and leukemoid reaction. Beside mental retardation, other anomalies could be treated or controlled by current medical care. The IQ of DS is around 20-80 with significant cognitive, language, and behavior problems (Dierssen, Ortiz-Abalia et al. 2006).