The screenning coagulation tests included PT, APTT, fibrinogen and platelet count have played an important role in providing for preoperative bleeding. Objectives: (1) Find out the rate and the characters of the abnormal parameters in the basic coagulation tests on preoperative patients. Patient and method: Crossectional descriptive study on 1700 preoperative patients. Results and conclusions: The rate of preoperative patients having abnormal coagulation tests is 14.41 percent, male 19.19 percent, female 10.68 percent. The rate of abnormal PT, PTL: aPTT: fibrinogen 6.76 percent, 6.41 percent, 5.58 percent and fibrinogen 1.35 percent. The kind of abnormal tests mostly found in Surgical ward is prolonged PT 10.2 percent, in Obstetries ward is reduced platelet's count 5.91 percent, in Otorhinolaryngology, Faculty odonto stomalogy and Eye ward is prolonged APTT with 6.52 percent, 4.34 percent and 6.25 percent.