Abstract: Objective To investigate the predictive value of the change rates of femoral and radial mean arterial pressures before and after fluid challenge for volume responsiveness in patients with early septic shock. Methods Fifty-two patients diagnosed with septic shock and needed volume resuscitation in the Department of Surgical Intensive Care Unit were enrolled between November 2012 and July 2014. All patients were monitored with pulse indicator continuous cardiac output（PiCCO）,left radial artery pressure and central venous pressure（CVP）and injected500 mL normal saline in the first 15 minutes. Femoral mean arterial pressure（MAPF）,radial mean arterial pressure（MAPR）,CVP and stroke volume index（SVI）were recorded before and after fluid challenge. The 28 patients with the SVI≥15% were assigned into response group and others into non-response group.Results The MAPF,MAPRand CVP significantly increased in the response group（74.4±7.7）vs（65.0±6.8）mm Hg,（69.9±10.4）vs（58.6±9.1）mm Hg and（11.8±2.6）vs（9.4±2.2）mm Hg,respectively,P＜0.01 for all. While in non-response group,MAPF,MAPR and CVP did not show significant change （71.8±8.0）vs（70.8±8.6）mm Hg,（67.6±10.7）vs（65.1±11.3）mm Hg,（11.9±4.0）vs（10.6±3.4）mm Hg,respectively;P＞0.05 for all.ΔMAPF（r=0.530,P＜0.001）andΔMAPR（r=0.427,P=0.002）were positively correlated with that of SVI as reflected by Pearson correlation analysis. In receiver operating characteristic curve analysis,ΔMAPF≥9.7% was regarded as an optimal cutoff with sensitivity of 75.0%,specificity of 79.2%,the area under curve of 0.822,andΔMAPR≥13.9% was regarded as an optimal cutoff with sensitivity of 67.9%,specificity of 70.8%,the area under curve of 0.757. ΔCVP was not correlated withΔSVI（r=0.057,P=0.689）,with the corresponding area under curve of 0.644. Conclusion BothΔMAPFandΔMAPRcan be used to predict volume responsiveness in early septic shock,whileΔCVP can’t. Compared toΔMAPR,ΔMAPFis more accurate in predicting volume responsiveness.