To detect the mutations of fibrillin-1 (FBN1) gene in the patients with Marfan syndrome (MFS), polymerase chain reaction (PCR) and denaturing high-performance liquid chromatography (DHPLC) were conducted to screen for the mutations in FBN1 gene. Sequence analyses were carried out when the DNA amplification fragments of the DHPLC elution profiles showed difference from the corresponding normal elution profile. Two novel mutations were detected in two families with MFS, respectively. One was a multiplex mutation in exon 55 containing a deletion mutation c.6862_6871delGGCTGTGTAG (p.Gly2288MetfsX109), a synonymous mutation (c.6861A>G) and an intronic mutation c.[6871+1_6871+11delGTAAGAGGATC; 6871+34dupCATCAGAAGTGACAGTGGACA], and the other was a missense mutation in exon 20 c.2462G>A (p.Cys821Tyr). The results indicated that the deletion mutation c.[6862_6871delGGCTGT GTAG; 6871+1_6871+11delGTAAGAGGATC] (p.Gly2288MetfsX109) and the missense mutation c.2462G>A (p.Cys821Tyr) of FBN1 gene may cause the two family patients with MFS respectively.