Anti-centromere antibody is a protein which is produced by immune system that mistakenly targets the body's own tissue. These autoantibodies are specific to centromere and kinetochore function. These are affiliated to the definite form of systemic sclerosis, and can be detachable in variable proportion of SS patients. ACA occur frequently in the limited systemic scleroderma and irregularly in the diffuse form of scleroderma. These antibodies will be seen rare in healthy persons. When a decreased likeness of aggressive internal organ involvement, such as fibrosis is noticed then these antibodies are present in the early stages of this disease. Nearly in 60% of patients with limited systemic scleroderma and 15% of those with diffuse form of scleroderma this antibodies are found. Anti-centromere test is done to differentiate between systemic scleroderma and diffuse form of scleroderma with similar symptoms.