Objective To observe histopathology changes in the main organs of Kunming (KM) mice after intraperitoneally injection of beryllium sulfate (BeSO₄·4H₂O). Methods Thirty 6-week old male KM mice were randomly divided into three groups, administered with saline solution of the beryllium sulfate by intraperitoneally injection every other day for two weeks. The organ coefficients were detected and pathological changes were examined by HE staining. Results Compared with the control group, the organ coefficients of testis, heart, spleen, kidney were not significantly changed, the organ coefficients of lung and liver were changed with significant differences (P<0.05). As for the liver and lung histopathology, it was normal in the control group, but the low dose experimental group presented congestion, hyperemia, bronchiectasic hemorrhage, slight alveolar inflammatory exudates, peribronchitis, interstitial pneumonia and lobular pneumonia. The lung tissue in the high dose experimental group presented bronchiectasic hemorrhage, severe bronchial inflammatory exudates, peribronchial alveolar ectasia, interstitial pneumonia, lobular pneumonia and confluent bronchopneumonia. Swelling of hepatocytes, and spotty and focal necrosis were seen in the liver of mice in the low dose experimental group. The high dose experimental group showed obvious liver damages such as swelling of most hepatocytes and disorganized arrangement of hepatocytes. A strong cytoplasmic vacuolar degeneration, obvious spotty and focal necrosis and inflammatory cell infiltration, acidophilic denaturation of hepatocytes surrounding the necrotic areas, slight pyknotic hepatocyte nuclei, more or less cytoplasmic rarefaction, apparent widening of hepatic sinusoids and central vein with denaturation and necrosis were often observed changes. The testis, heart, spleen and kidney in the model group showed normal histopathological appearance. ConclusionsBeryllium sulfate injected intraperitoneally in the doses used in this study induce apparent damages in the lung and liver tissue of mice, but other organs are not obviously affected.