Knee osteoarthritis (OA) is a major cause of pain and functional limitation. Short-term Baduanjin () exercise had been testified to be beneficial to the disease. This study conducted an initial assessment of the one-year Baduanjin exercise on knee OA.The recruited patients practiced Baduanjin at the community recreational center. Sessions were held for 30 min five times a week for one year. Knee pain, stiffness, physical disability, general health, knee extensors and flexors strength, and aerobic ability were measured using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), the Medical Outcomes Study Short Form-36 (SF-36), the 6-Minute Walk Test (6-MWT), and the Isokinetic Strength of the Knee Extensors and Flexors (ISKEF). Body mass index (BMI) was also calculated before and after the study period for comparison.Twenty-eight patients signed the informed consent. Six patients withdrew from the trial. Twenty-two patients (29 knees) completed the one-year study. After one-year Baduanjin exercise, WOMAC pain (132.0±69.6 vs. 56.2±67.6, P=0.000), stiffness (64.7±54.8 vs. 22.3±34.6, P=0.000), and physical function subscales (386.1±275.8 vs. 182.0±235.7, P=0.003); SF-36 body pain (45.7±20.0 vs. 57.4±17.9, P=0.005), general health (50.5±20.0 vs. 62.1±16.1, P=0.004), role emotional (64.4±26.1 vs. 73.5±21.3, P=0.047), and health transition (3.3±1.0 vs. 2.6±1.0, P=0.008); BMI (25.0±2.9 vs. 24.4±2.9, P=0.032); 6-MWT (565.7±94.6 vs. 610.5±66.7, P=0.036); and ISKEF Peak Torque (the Knee Extensors: 60.5±25.5 vs. 76.8±31, P=0.000; the Knee Flexors: 29.3±15.9 vs. 37.1±15.8, P=0.001) were significantly improved. No adverse effects resulted from the exercise.It suggested that the long-term Baduanjin could be a feasible and safe exercise option for knee OA.