Objective To investigate the toxicity of Caulis Aristolochiae Mansshuriensis(CAM).Methods 50 SD rats were divided into three groups:S and B groups which were given daily dose of 6g and 1g CAM in 2ml respectively,and control group,which fed with 2ml water.At 7 day after,urinary volume,urinary sugar,urinary protein,blood creatinine were measured,and B group was sacrificed for kidney pathological examination.At one and two month after,those of S and control groups were measured again.Of S group,10 rats were sacrificed for kidney check.At 3 month after,those did again,and all of them were sacrificed.Results 2 rats of B group died showing the kidney necrosis.The difference between S and control groups was of no significance (P>0.05).Conclusion High dose of CAM damaged the kidney,resulting in acute renal tubules necrosis.;