Reflex sympathetic dystrophy (RSD) is an uncommon complication after surgery. RSD often occurs in upper limbs. The real mechanism and optimal treatments of RSD are undetermined. The association of RSD with total knee arthroplasty operation has been reported scarcely. We report a 76 year-old female develop deep aching pain, allodynia and skin temperature change after knee replacement surgery. This lady undertook regional sympathetic blocks and physical therapy. After treatment, the patient achieved satisfactory result and was regularly followed up in our clinics.