Objective: To study the mechanisms of the injury of the cytomembrane and cytoskeleton of cultured myocardial cells exposed to the combined stimulation of hypoxia and burn serum. Methods: The myocardial cells of neonatal rats were cultured in vitro. The changes of the cytoskeleton and cytomembrane of the cultured myocardial cells before and after the combined stimulation of hypoxia and burn serum were observed dynamically with immunohistochemistry, flow cytometry and viscoelasticity determination technique. The deformity of the cultured myocardial cells was determined mathematically. Results: In the early stage after the combined impact of hypoxia and burn serum, the cultured myocardial cells were deformed. The elastic coefficient k1 and k2 and the viscosity coefficient μ of the cytomembrane were significantly decreased (P < 0.05 - 0. 01 ). The fluorescent intensity of the cytoskeleton protein and the number of the intermediate filaments and imcrotubules were markedly decreased. Conclusion: The cytoskeleton is essential to the integrity of the cytomembrane. The damage of the cytoskeleton induces the increase of fragility and decrease of viscoelasticity of the cytomembrane . These changes of the biomechanic characteistics participate directly in the initiation and development myocardial damage. Objective: To study the mechanisms of the injury of the cytomembrane and cytoskeleton of cultured myocardial cells exposed to the combined stimulation of hypoxia and burn serum. Methods: The myocardial cells of neonatal rats were cultured in vitro. The changes of the cytoskeleton and cytomembrane of the cultured myocardial cells before and after the combined stimulation of hypoxia and burn serum were observed dynamically with immunohistochemistry, flow cytometry and viscoelasticity determination technique. The deformity of the cultured myocardial cells was determined mathematically. Results: In the early stage after the combined impact of The elastic coefficient k1 and k2 and the viscosity coefficient μ of the cytomembrane were significantly decreased (P <0.05-0.01). The fluorescent intensity of the cytoskeleton protein and the number of the intermediate filaments and imcrotubules were markedly decreased. Con clusion: The cytoskeleton is essential to the integrity of the cytomembrane. The damage of the cytoskeleton induces the increase of fragility and decrease of viscoelasticity of the cytomembrane. These changes of the biomechanic characteistics participate directly in the initiation and development myocardial damage.