Abstract:[Objective] To evaluate the clinical efficacy of proximal humeral internal locked system plates (PHILOS) for internal fixa- tion of Vancouver type B1 and B2 periprosthetic femoral fractures. [Methods] From September 2017 to January 2019, 7 patients had peri- prosthetic femoral fractures fixated with PHILOS plate, including 5 cases of Vancouver type B1 and 2 cases of type B2. Of them, 5 males and 2 females aged 57 to 86 years with an average of (71.71±9.11) years. [Results] All the 7 patients were successfully operated on without serious complications, such as postoperative incision infection and deep venous thrombosis. The patients were followed up for 12~24 months, with an average of (17.29±3.86) months. The Harris scores increased significantly over time postoperatively (P<0.05) . At the latest follow-up, 5 patients were able to walk freely, while the remaining 2 patients resumed full weight-bearing walking with the aid of a walker. Radiographically, all patients had periprosthetic fractures healed, without loosening of the femoral prosthesis, and with no failure of PHI- LOS plate. [Conclusion] The PHILOS plate used for the treatment of Vancouver type B1 and B2 periprosthetic femoral fractures has bene- fits of simplifying surgical operation and decreasing medical cost.