OBJECTIVE: To examine the function change of myocardial calcium transports and determined what role the change plays in cardiac dysfunction after severe burn injury in rats. METHODS: The contraction and relaxation properties of the left ventricle (LV) were studied in the isolated hearts preparations of Wistar rats at 3, 8, and 24 h after a 30% TBSA (total body surface area) full-thickness burn. The calcium transport function of the sarcoplasmic reticulum (SR) was measured by the millipore filtration technique. RESULTS: The maximal rate of LV pressure (plus minusdp/dtmax) of the burn group was significantly lower than that of the control group (P<0.01). In addition, the calcium-dependent ATPase activity and the coupling ratio of SR were also markedly depressed. CONCLUSIONS: It indicates that the decrease in the SR calcium transport function is one of the important mechanisms for the cardiac contractile dysfunction after severe burn injury.