Purpose: This study was to identify the factors influencing depression among patients with degenerative arthritis after total knee arthroplasty. Methods: The subjects were 108 patients who admitted or visited K hospital in K city after total knee arthroplasty. Data were analyzed using SPSS WIN 18.0 program. Results: The level of depression was 2.72 with a possible range of 1 to 5. Social support was 3.71 out of a total score 5. Self-efficacy was 64.47 ranged from 10 to 100. Self-esteem was 2.59 ranged from 1 to 5. The associated factors with depression were marital status, length of illness, perceived health status, pain, social support, self-efficacy, and self-esteem. Marital status, length of illness, and perceived health status accounted for 5.8% of depression. Next, all variables including pain, social support, self-efficacy and self-esteem accounted for 66.4% of depression. Conclusion: The level of depression among the subjects significantly be related to marital status, length of illness, perceived health status, pain, social support, self-efficacy and self-esteem. It indicates a need to develop nursing interventions for them to decrease depression and develop quality of life during recovery.