Context: Partial 17a-hydroxylase/17,20 lyase deficiency (17OHD) is a rare subtype of 17OHD caused by CYP17 gene mutations. Objective: Five Chinese 46,XX patients and one family with partial 17OHD were genotyped. Patients: The five patients derived from different families and one of them had another patient in family. The diagnosis of partial 17OHD was established through clinical and laboratory characteristics in Peking Union Medical College Hospital, China, from 2000 to 2010. Results: Seven CYP17 gene mutations are identified from these patients. Among them, R449C and L209P are two novel missense mutations. Four patients are found to have a compound heterozygous mutations and one patient has only one mutation. The patients with family history are also found to have parent origin of gene mutations. Conclusion: Two novel missense mutations in CYP1 7 are found in this study. Comparing with previous reports, the different combination of mutations may have various effects on the activities of the 17-hydroxylase and/or17,20-lyase.