Congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency is one of the most common autosomal recessive disorders. The disease causes due to CYP21A2 mutations. Mutation analysis of CYP21A2 gene plays an important role in diagnosing of CAH disease, carrier detection, prenatal diagnosis and treatment. The study was to detect the mutation in CYP21A2 gene. The results indicated that all patients were detected to have mutation in CYP21A2 gene including: 1/5 patient had large deletion, 2/5 patients had In2 A/C-+G mutation, 1/5 patient had I172N mutation and 1/5 patient had R356W mutation. In conclusion, successfully identify the mutation in CY21A2 gene using sequencing and MLPA techniques.