Objective To observe the pathological changes of liver cells in the early periods of burn injury combined with endotoxemia and to explore its mechanisms preliminarily. Methods Rats were inflicted with 20% TBSA Ⅲ degree burn combined with intraperitoneal injection of lipopolysaccharide (burn injury combined with endotoxemia, combined group) or simply burned or simply injected. Each group included 25 rats, with 5 rats left for control. Rats in the former 3 groups were sacrificed and sampled at 1, 3, 6, 12 and 24 h after injury, 5 rats for each time point. The results were observed by HE staining, TUNEL and DNA gel electrophoresis, and the concentrations of plasma MDA and the activity of plasma SOD were assessed and analyzed. Results Apoptosis of liver cells was found in each of the 3 groups but its regularity was different from one another. Much more apoptotic cells in the combined group were found than the other 2 groups and apoptosis happened earlier with its maximum at 6 h postinjury and declined thereafter. Much less apoptotic cells were found in the simply burned group and reached the maximum at 12 h postburn. There were only a few apoptotic cells at 6 h postinjection in the simply injected group in which there were the fewest apoptotic cells in the three groups. The concentration of plasma MDA and the activity of SOD always moved in the opposite way at the same time. In the combined group, the maximum of MDA concentration and the minimum of SOD activity happened at the same time point, which was just before the one of the maximum of liver cell apoptosis. Conclusion During the early period of burn injury combined with endotoxemia, rat liver cells die mainly in the apoptotic way, with lots of apoptotic cells at 6 h and 12 h postinjury, combined with necrosis at 24 h. Lipid peroxidation may partly account for the apoptosis of liver cells.