Abstract:  Objective To explore the clinical features of Marfan syndrome (MFS) and its virulence gene mutation of FBN1. Methods Clinical data of 2 children with MFS were retrospectively analyzed, and pertinent literatures were reviewed. Results Case one was a 1 year and 10 months old boy with a special face, bilateral lower eyelid edema, high palatal arch, slender fingers and toes. A little of moist rales in lung could be heard, and systolic accentuated in apex could be heard too. Echocardiography showed that aortic coronary sinus dilated, aorta and pulmonary artery broadened, left ventricular diverticulum, a small amount of mitral regurgitation,and moderate tricuspid regurgitation. Electrocardiogram showed incomplete right bundle branch block. Gene detection found a c.3037G ＞ A mutation (p.Gly1013Arg) in FBN1. Case two was a 12 years old slender boy with spider-like finger/toe, high myopia, 2/6 systolic and diastolic murmur in the first and two auscultation area in aortic valves. Echocardiography showed the aortic sinus significantly broadened, aortic incompetence, mild pulmonary regurgitation and left ventricular enlargement. Gene detection found heterozygous mutation of c.1876G ＞ A (p.Gly626Arg) in FBN1, which has not been reported. Conclusion The diagnosis of MFS can be confirmed by FBN1 gene detection. A new mutation of c.1876G ＞ A (p.Gly626Arg) was detected.