Objective To develop an instrument for evaluating adherence to homebased rehabilitation among patients with total knee arthroplasty. Methods Based on literature review and group discussion, we developed an initial homebased rehabilitation adherence scale for patients with total knee arthroplasty. Then a 2round expert consultation and a pilot survey with 176 patients with total knee arthroplasty were conducted to validate the scale. Results More than eighty percent (84.62% at round 1, 81.82% at round 2) of the experts returned the questionnaire. The Kendall′s coefficient of concordance (W) was 0.332 and the authority coefficient was 0.839. Exploratory factor analysis showed the scale included 3 dimensions and 11 items, which could explain 69.855% of the total variance. The itemlevel content validity index (CVI) ranged from 0.889 to 1.000 and the scalelevel CVI was 0.978. The Cronbach′s α coefficients were 0.747-0.885 for 3 dimensions and 0.850 for the total scale. The correlation coefficients between dimension and the total scale ranged from 0.622 to 0.865. Conclusion The scale can be used to measure adherence to rehabilitation at home among patients with total knee arthroplasty for its rational development process and high reliability and validity.