Levels of factor VIII, factor VII-X, factor X, factor V, fibrinogen, antithrombin III, euglobulin lysis times, plasminogen, α2-macroglobulin, α1-antitrypsin and FDP were determined in 487 healthy normal subjects from age 20 to 94. In subjects over age 60, serum lipids were determined simultaneously.In the subjects over age 60, levels of factor VIII, fibrinogen, antithrombin III, α2-maeroglobulin, α1-antitrypsin and FDP were higher, factor V activity was lower, and euglobulin lysis times were shorter than in subjects under age 50. In the older subjects, levels of factor VII-X, factor X fibrinogen, antithrombin III, plasminogen and FDP showed slight but progressive decline with age. In these subjects over age 60, serum cholesterol levels were significantly correlated with levels of factor VII-X, factor X, antithrombin III, plasminogen and FDP; antithrombin III concentration was significantly correlated with factor X activity but not with factor VII-X activity; euglobulin lysis times were correlated with obesity.