Abstract: Objective To discuss the common virulence gene mutation in seven Lynch syndrome families from Yunnan Province. Methods We selected seven families treated at Department of Oncology, The First Affiliated Hospital of Kunming Medical University from March 2008 to December 2013. These families were confirmed as MSI-H and dMMR propositus through immunohistochemical detection and microsatellite instability detection and also they met the AmsterdamⅡ diagnostic criteria. By adopting the target area acquisition combined with the deep sequencing technology, we analyzed five gene exon and their neighbouring ±2bp intron area mutation related to hereditary colorectal cancer in the first-episode patients in these kindreds. Results Among seven families, including two Bai families, two Yi families and three Han families, the known mutation were not found in the four minorities' pedigrees. Conclusion Pedigree Lynch syndrome mutation maybe varies by nationality.