RESUMEN
<p><b>AIM</b>To establish reference range of blood theology for different gender by sitting and lying in healthy populations.</p><p><b>METHODS</b>In 31 volunteers blood were drawed in the postures of sitting and lying to measure blood rheology. Data (between July 2002 and July 2006) of 32854 samples (23436 check-up, 6553 out-patient,2865 in-patient) were collected. Differences between different postures and different gender were compared by Independ-Sample t-test with SPSS 13.0 software and each reference range of blood rheology was established.</p><p><b>RESULTS</b>In sitting and lying postures 12 parameters of blood rheology showed great significance (P < 0.01). 8 parameters such as whole blood viscosity, blood reduce viscosity, plasma viscosity, hematocrit, were decreased by 9.33% on average while posture was changed from sitting to lying. But index of erythrocyte deformability, erythrocyte electrophoresis presented inverse correlation and were increased by 6.49% on average with the same posture change.Various parameters of blood theology in different gender showed great significance (P < 0.01).</p><p><b>CONCLUSION</b>There is significant difference in various parameters of blood rheology in the posture change from sitting to lying. Reference ranges of blood theology of different postures are established which may be used to decrease the rate of misdiagnosis by 8-10 percent.</p>