Objective To dynamically measure cardiac output in shock neonates and to explore its clinical values.Methods The cardiac output and stroke volume of left ventricle in 30 shock neonates and 30 normal neonates were measured by noninvasive ultrasonic cardiac output monitor (USCOM) and the measurement was repeated in shock neonates after volume expansion and dopamine(2-4μg/(kg·min))treatment.Results The cardiac output and stroke volume of left ventricle in shock neonates ((0.36 ± 0.24) L/min,(3.5 ± 1.5) cm~3) were significantly lower than those in normal neonates ((0.49 ± 0.15) L/min,(2.7 ± 1.6) cm~3)) and however were improved significantly after volume expansion and dopamine treatment ((0.52 ± 0.28) L/min,(3.8 ± 1.8) cm~3).The urine volume was also increased significantly after treatment (P < 0.05).Conclusions Dynamic measurement of the cardiac output in early shock neonates might offer guidance on clinical fluid resuscitation.