Background: Dengue haemorrhagic fever is one of the important infectious diseases in Vietnam. Studying the para clinical, clinical characteristics and prognostic factors to diagnose and treat early reducing the mortality of DHF. Ojective: Determine the paraclinical, clinical characteristics and find out prognostic related factors to Dengue hemorrhagic fever in adults. Method: Description, cross-sectional study, using the SD Bioline KIT NS1, IgG/IgM rapid test for determining dengue virus infection, testing Hct, leukocyte, platelet, AST, ALT, bilirubin, PT, aPTT and Fibrinogen, ECHO. Result: Research 146 DHF patients: DHF 45.2 percent, DHF waming sign 48.6 percent and severe DHF 6.1 percent, 100 percent of DHF patients have fever and a sudden high fever, days of averaged fever 5.9 + or - 1.2 days from 3-10 days, petechiae 89.7 percent, internal bleeding 1.3 percent, hepatomegaly 13 percent, high Het 31.4 percent, pleural effusion 21.9 percent, peritoneal effusion 28 percent, i edema of gallbladder 28,7 percent, platelet 10G / L. the 6-7day 90.8 percent, Leukopenia 64.71 percent. Recovery 99.3 percent, mortality 0.7 percent. Signs before the shock: discomfort 100 percent, abdominal pain 11.1 percent, cold extremities 100 percent, sudden temperature drops 88.8 percent, pulse 100 beats / minute 100 percent, hepatomegaly 33, 3 percent, pleural effusion 66.6 percent, peritoneal effusion 77.7 percent, increased bleeding 33.3 percent, vomiting 22.2 percentt. Severe prognosis factors: abdominal pain 9.7 percent, discomfort 100 percent, cold extremities 100 percent, pulse 100 beats / minute 41.1 percent, increased bleeding 100 percent, edema of gallbladder 14.2 percent, pleural effusion 18. 7 percent, peritoneal effusion 17 percent. Conclusion: Understanding clearly the para clinical, clinical characteristics and prognostic factors to diagnose and treat early reducing the mortality and treating DHF with guideline of Ministry of Health is good result.