Abstract: Objective To study the effects of chronic arsenic poisoning on configuration and apoptosis of renal glomerulus cells.Methods Rat models of chronic arsenic poisoning were made.The change of configuration and apoptosis of renal glomerulus cells was obser ved with HE,immunohistochemistry method(Tunel method)and the image pattern analysis.Results Congestive renal blood vessels,inter cellular edema,increased renal glomerulus cells were found in rats of chronic arsenic poisoning with swelled glomerulus,hyperchromatic and contracted nucleus of apoptotic cells.The number of apoptotic cells significantly increased in the groups of rats with high-dose(34.10±6.49)and low-dose(1.50±1.18)arsenic poisoning compared to the controll group(10.27±3.51;1.50±1.18).Conclusion Chronic arsenic poisoning may result in the proliferated glomerulus cells and may correlated with the increased apoptosis of renal glomerulus cells.