Abstract: We studied the changes of potassium and sodiumcontents in erythrocytes and the activity of ewthrocytemembrane Na+ - K+ - ATPase in 4o cardiac blood samples of rabbit corpses at different postmortem intervals(PMI). The erythrocyte potassium content (RBCK) decreased linearly as the PMI increased (R = - 0. 829, P＜0. 025). during postmortem 48 hours. The erythrocytepotassium content and the time after death had significantcorrelation. The activity of erythrocyte mernbrane Na+ -K + - ATPase had no significant changes over postmortem48 hours.

Key words: postmortem interval, potassium ion content, sodium ion content, Na~+-K~+-ATPase