Objective To compare the effects of continuous femoral nerve block (CFNB) and intravenous patient controlled analgesia(IPCA) on postoperative analgesia and rehabilitation therapy for patients after knee arthrolysis. Methods 60 patients were randomly allocatedinto CFNB group (n=30) in which patients received CFNB via a catheter inserted in femoral sheath and IPCA group (n=30) in which patientsreceived IPCA via an intravenous infusion pump contained with analgesics. All patients were successively offered passive rehabilitationtherapy and active rehabilitation therapy at 6, 24, 30, and 48 h post-operation. An injection of 50 mg ropivacaine (0.25%) was administratedvia the catheter before rehabilitation therapy in CFNB group. Analgesics (200~250 μg sufentanil and 100 mg ketamine in 100 ml normalsaline) were transfused intravenously at a constant rate during the whole postoperative period in group IPCA. Visual Analogue Score(VAS), active flexion angle (AFA) of suffered knee joint, and side effects related to CFNB or IPCA were recorded. Results The VAS scoreand the side effect rate were lower in CFNB group than in IPCA group (P<0.05). And the AFA was significantly larger in CFNB group thanin IPCA group (P<0.001). Conclusion CFNB is a safe and beneficial analgesia for patients in postoperative rehabilitation.