Abstract: On observing the microcirculation blood flow of 52 rats suffering from cremaster muscle hemorrhagic shock in vivo the microvessels in 150μm diameter on the average,the diameter of RBCs column,the pseudo shear rate are measened,and other microcirculation parameters are determince using the digital image technique of Xiu's lab in the Institute of Microcirculation.Chinese Academy of Medical Scienccs.A new microcirculation blood flow parameter,RBCs dispereion which is equal to the ratio of RBCs column diameter to vessel diameter in microvesscls is put forward to describing effectively the disorder phenemena the microvessel blood flow when microcirculation barrier appears.The relation betwccn RBCs disperoion and pseudo shear rate are analysed according to experimental data.The examination through RBCs dispereion is more effective than that of HCT to reflect the pathological information of disorder microvessel blood flow.