Objective <p>To explore the behavioral characteristics and brain mechanism of short-term memory changes in children with congenital heart disease before and after operation.</p> Methods <p>Twenty children aged 6 ~ 9 were tested with functional magnetic resonance imaging (fMRI) and short-term memory behavior 1 week before and 2 weeks after operation, and the data before and after operation were analyzed by paired t-test.</p> Results <p>The values of ALFF after operation in left inferior temporal gyrus, middle temporal gyrus, right superior temporal gyrus and bilateral anterior cingulate gyrus were lower than those before operation, and the correct rate of short-term memory after operation was lower than that before operation. The ALFF values of bilateral anterior cingulate gyrus and right superior temporal gyrus were positively correlated with the correct rate of active memory tasks.</p> Conclusion <p>The impact of congenital heart surgery on children’s short-term memory may be related to changes in the functions of the temporal lobe and the anterior cingulate cortex.</p>