Objective To investigate guiding value of bedside ultrasound on capacity responsiveness in children with septic shock. Methods 68 children with septic shock were selected in hospital from October 2014 to October 2017, who received rehydration treatment. According to reaction condition, children were divided into two groups.37 children had no response (increasing of SV＜15%) as control group.31 children had response (increasing of SV≥15%) as observation group. Bedside ultrasound detected before and after rehydration. Results Compared between two groups before rehydration, heart rate, dilatation index of inferior vena cava, respiratory variation rate of aortic peak flow velocity, maximum velocity variation of brachial artery in observation group were higher than control group (P<0.05). Mean arterial pressure and intrathoracic blood volume index in observation group were lower than control group (P<0.05). Compared intra group after rehydration, heart rate, dilatation index of inferior vena cava, respiratory variation rate of aortic peak flow velocity, maximum velocity variation of brachial artery decreased in observation group(P<0.05). Mean arterial pressure and intrathoracic blood volume index increased in observation group(P<0.05).There were no significant change on heart rate, dilatation index of inferior vena cava, respiratory variation rate of aortic peak flow velocity, maximum velocity variation of brachial artery, mean arterial pressure, intrathoracic blood volume index in control group(P>0.05). Compared between two groups after rehydration, there were no significant difference on heart rate, dilatation index of inferior vena cava, respiratory variation rate of aortic peak flow velocity, maximum velocity variation of brachial artery, mean arterial pressure, intrathoracic blood volume index between two groups(P>0.05). Conclusion Bedside ultrasound can be used to guide fluid replacement therapy in children with septic shock.