<正> This study reports the dynamic changes of whole blood and plasmaviscosity

reduced viscosity of whole blood

hematocrit

erythrocyte sedimentationrate（ESR）and K value of ESR equation in the different phases of 130 patientswith epidemic hemorrhagic fever（EHF）

in comparison with their normal ranges.There were significant changes（P<0.05～0.01）in the above mentioned itemsexcept for ESR in the febrile phase

ESR and K value of ESR equation in thehypotensive phase

and plasma viscosity in the diuretic and convalescent phases.Clinically

the whole blood viscosity increased by 24% during the hypotensivephase and by 18.7% during the febrile phase.The authors believe that the increaseof the whole blood viscosity could slow down the blood circulation

and decreaseoxygen saturation of the tissue and cardiac output.Thus

it is an effectivemeasure to control the rising of the whole blood viscosity in the treatment of EHF.