Objective To modify femoral resection method in primary total knee arthroplasty and verify the operative results of this modification through measurement of the thickness of the bone resection and clinical follow up. Methods The femoral resection measurement guide was modified so that the resection of the posterior femoral condyle was increased 3 mm in thickness. A total of 81 cases undergoing total knee replacement were divided into varus group and valgus group, in which the thickness of various resections were measured and compared with that of the prosthetic implants. The average follow-up time was 27.1 months. Results On average, the thickness of bone resection in both the flexion and the extension gaps was smaller than that of the prosthesis. In both groups, except for the thickness of the posterior femoral condyle, there were significant differences in other indices ( P