The earlier diagnosis of DIC before its overt stage is necessary for earlier treatment and for the good outcomes.In 2001, the Scientific and Standardization Committee of the International Society on Thrombosis and Hemostasis(ISTH) proposed new diagnostic criteria for the diagnosis of overt and non-overt, preclinical DICs.We investigated clinical usefulness of ISTH non-overt DIC criteria with some modification for earlier diagnosis.We enrolled 320 patients who had been admitted and having D-dimer studies from March 2010 to September 2010 at the Gangnam Severance Hospital, Seoul, Korea.Hemostatic tests including platelet counts, PT, serum fibrinogen, D-dimer levels with antithrombin and protein-C levels were evaluated respectively rejecting the negative scores.The mortality rates were pursued during the study period.Student T test was used statistically.There were significant parameric changes including D-dimer studies in each stage of DICs.In patients with nonovert DICs, protein-C and antithrombin levels were decreased almostly as in overt DICs, but more earlier than overt DICs.One hundred thirty two (41.5%) patients had no DIC,but 15 patients died with 11.4% mortality rate.One hundred tenty two (38.1%) patients had non-overt DICs and 37 patients died with 30.3% mortality rate.Sixty six (20.4%) patients had overt DIC and 45 patients died with 68.2% mortality rate, higher than non-overt DICs patients (p< 0.05) with 71.2% sensitivity and 57.9% specificity.ISTH non-overt DIC criteria with rejecting negative scores and scoring more than 5 points are useful for earlier detections 0fnon-overt DIC stage to improve our outcomes.