Clinical evaluations of various laboratory data from immuno-serological tests such as rheumatoid factor, anti-nuclear antibody, and other auto antibodies were reviewed. Rheumatoid factors (RF) were discussed in relation to positivity in various diseases, immunoglobulin class of RF, and correlation between titers of RF and circulating immune complex (IC). As a result, higher frequency and higher titers of IgA-RF were found in Sjögren syndrome patients. Titers of RF did not show disease activity of RA, but those of ESR and CRP did. Anti-nuclear antibodies (ANA) were discussed in relation to positivity in healthy subjects, specific antibodies and corresponding specific disease, correlation among titers of anti-dsDNA antibody, CH50 and circulating immune complex. As a result, an ANA frequency of 40% was found in healthy young women. Values of CH50 were much better than ANA titers for evaluating clinical activity in SLE patients. Findings of anti-cardiolipin antibody in thrombosis patients with connective tissue vascular disease (CVD), anti-centromere antibody in various CVD patients as well as CREST patients and primary biliary cirrhosis patients and anti-neutrophil cytoplasmic antibodies in various vascular diseases along with inflammatory bowel disease patients were presented. Finally, useful laboratory data at different clinical steps such as diagnosis, evaluation of disease activity and estimation of prognosis were demonstrated in CVD.