Juvenile Rheumatoid arthritis (JRA), is the most frequent pediatric connective tissue disease. JRA encompasses group of disease in children all characterized by the presence of arthritis with or without extra articulator manifestations.Juvenile Rheumatoid arthritis is the not rare, ther are about 5% of alľ cases of rheumatoid arthritis begin in childhood, usually not before the second birthday. Juvenile Rheumatoid arthritis is the most common pediatric rheumaticdirease, with an annual incidence of about 1-4cases per 10.000 children and prevalence of 0.5 to I case per 1000.The cause of JRA is unknown; there may be multiple etiologic events or single pathogen vector multiple clinical patterns evolving from interaction with cause JRA; possible causes include infection, immunity,trauma, stress and immuno – genetic predisposition. JRA is characterized by 3 pathogenic mechanisms: Chronic inflammation of the synovial membrane.•Enhanced pathogenic T&B cells dependant immunoreaction including auto-immuno Phenomenon.•Hyperplasia of the synovial tissues.Extra–articular pathology include pericardium, pleura and peritoneum, skin eruption, ocular changes, Rheumatoid nodules, lymph nodes enlargement, Hepatic histopthology and renal change.JRA patients are classified by type of onset into:•Systemic onset disease.•Polyarticular rheumatoid factor negative.•Pulyarticular rheumatoid factor positive.•Puuciarticular disease associated with chronic iridocyclists (type 1), and pouciarticular disease associated with sacroilitis (type II).The characteristic clinical features of systemic disease are marked extra – articular . Manifestation such as high intermittent fever, rash, Hepatosplenomegally, lymphadenopathy, pericarditis, anemia and occasional disseminated interavaular coagulopathy.Diagnosis of Iuvenile Rheumatoid arthritis rests solely on clinical recognition of disease. The sources of data are used to arrive at a diagnoses of a rheumatic disease include history and physical examination, laboratory tests, Radiographs and imaging procedures, and synovial fluid.Laboratory studies of limited value for diagnosis because findings are variable and lack specificity. These studies include tests for acute phase phenomena which include: Sedimentation rate, C- reactive protein serum mucoproteins various alphagobulins, gamma globulines, some complement components a certain proteins such as transferring. Rheumatic factors, antinuclearantibodies, serum complement and its components, immune and the histo compatibility antigens. Other tests which may be useful such as blood count and urine analysis. The importance in using technology is to improve the sensitivity of diagnosis initially and with flare ups. Plain radiography can be used in children whom it is difficult to get an accurate history. Even when plain films are positive early in the course of childhood arthritis, the finding are non- specific. Ultrasound is clinically used to evaluate symptomatic sites of pain or swelling for specific finding as fluid. A varieties of vascular sonography called color power angiography (CPA) or power Doppler has recently become available of vascular sonography callecd color power.CT and MR imaging are best reserved for the patients whose clinical question can most be answered with plain radiography or ultrasound. Medical management is the commonest way of treating children with JRA. Some drugs have specific side effects in children such as cortcosteroid on growth. Persisting joint inflammation can be treated either by synoviorthesis or with arthrascopic synovectomy. Reconstruction surgery can be used in older children and adolescents. Cervical spine involves increases anesthesia risks because of limit mouth openin.Rehabilitation is very important in management of JRA. Stretching and splints reduce flexion contractors occupational therapy helps with activities of daily living. Of those children who have systemic onset I /50% well remit without recurrence. The remaining 50% will have a Polyarticular course with 33% having a sever destructive arthritis and local generalized growth abnormalities. Of children with systemic onset IRA,4% die from infection or amyloidoses.