The knee is affected to osteoarthritis more than any other joints. Knee osteoarthritis causes pain, inflammation, quadriceps muscle atrophy and tightness of hamstring muscle. The aim of this study is comparing the effects of electroacupuncture and low level laser on knee osteoarthritis. This study is a double blind clinical trial because both of patient and assessor are not aware of kind of treatment methods but therapist is aware kind of treatment methods. Sixty patients will refer to clinic of Fattemieh physiotherapy in Rafsanjan. Assessor evaluates the patients based on inclusion criteria, then he divided them to random permuted blocks methods in 3 equal groups and refers to therapist. Three interventions of this study are electroacupuncture (acupuncture associated with electricity), low level laser (Gallium, Aluminum- Arsenide, 810 nm, 100mv) and Placebo. Intensity of pain, movement, inflammation and 6 minutes walking test of knee osteoarthritis assessed during 1st, 5th, 10th sessions and one month after end of treatment. Inclusion criteria are having 45-75 year, knee pain more than 3 months, ability of walking, osteophyte in knee, reduction of joint space, crepitation of knee movement, grade 2 and 3 osteoarthritis of the knee and primary osteoarthritis of the knee. Exclusion criteria are injection of corticosteroids during previous 1 month, fracture, dislocation and previous surgery of the knee, pregnancy, rheumatoid arthritis and sever knee osteoarthritis (grade 4).