Abstract: Objective Toexplore factors affecting range of motion in patients accepting total knee replacement with high flexion prosthesis. Methods FromAugust 2013 toAugust 2014, 182 patients accepting total knee replacement with high flexion prosthesis whoaccordedwith our selection criteria were included. The following data were selectedby the means of questionnaire: gender, age, body mass index (BMI), diagnosis, patella resurfacing, preoperative ROM, application time of tourniquet, flexion deformity, HSS score and ROM of 12 months after surgery. The data were recordedand analyzed. Results There were 62 males and 120 females in this study with mean age of 63.2 years. The results showedthat knee ROM of patients in osteoarthritis (OA) and patella resurfacing groupwas better than that of patients in rheumatoidarthritis (RA) and patella non-resurfacing group. Secondly, in comparison with patients whose postoperative ROM was less than 125°, lower BMI, greater ROM before surgery, less tourniquet time, less level of deformity and better HSS score were foundin patients whose postoperative ROM was greater than 125° (P＜ 0.05). Finally, multivariate analysis showedthat RA, non-resurfacing and preoperative ROM＜ 100° were risk factors for postoperative ROM less than 120° (P＜ 0.05). Conclusion The factors relatedtothe final ROM for patients whoacceptedhigh flexion prosthesis include BM I, preoperative HSS scores, patella resurfacing, preoperative ROM and deformity.