A diagnostic accuracy study was adopted to evaluate the ability of Cerebral edema monitor by comparing the index test results with those of the reference standard. The serum levels of astrocyte S100 protein and neuron-specific enolase (NSE) were determined. Changes in the cerebral electrical impedance coefficient (CEIC) was detected with the BORN-BE monitor. The left- and right-sided CEIC values, serum levels of S100, and serum NSE in the CPB group significantly increased from the beginning to the end of the operation (P < .05). Furthermore, left and right-sided CEIC values, serum levels of S100, and serum NSE in the CPB-B group were significantly higher than those of the CPB-A group (P < .05). Detection rates of cerebral edema in the CPB-B group at the 24 h post-operative time point were significantly higher than those in the CPB-A group (P < .05). The degree of brain damage is positively correlated with the CPB and aortic cross-clamping. CEIC is a sensitive index reflecting brain damage during CPB in infants.