To explore the clinical characteristics of the dengue serotypes, 59 patients who were diagnosed with dengue hemorrhagic fever by RTPCR and were treated at National Hospital for Tropical Disease in the period from 08/2011 to 07/2012 has been studied. Results: The common clinical manifestations were: fever, headache, muscles pain, joints pain, skin hyperemia (all the patiens) and hemorrhage (64,4 percent). Less common manifestations were retro-orbital pain (52,5 percent), nausea (47,5 percent), red maculopapular (47,5 percent), vomiting (23,7 percent), lymphadenopathy (22 percent). There is no difference in clinical manifestation of DEN-l and DEN-2 infection (p 0.05). The hematocrit increased and platelets decreased from 3rd day of illness
leukopenia decreased from the 2rd day, all three indicators recovered on the 10th day of illness. Dengue serotypes infection had an increasing of ALT, AST and decreasing of PT, fibrinogen. In DEN-2 infection, platelets decreased lower (p 0.05) and earlier than the other dengue serotypes. This study showed that: keep on study about the clinical characteristics of the serotypes to help prognosis the outbreaks of dengue.