·AIM:To observe the acute toxicity of nickel sulphate in SD juvenile rat,and to determine the LD50.·METHODS:The LD100 in rat by ip injection was preliminarily measured to be 49.00mg/kg,and LD0 was 25.00mg/kg,then 70 rats were divided into 5 groups randomly,the doses of every group were 25.00mg/kg,29.58mg/kg,35.00mg/kg,41.39mg/kg,49.00mg/kg,the interval between groups was set at 1.183∶1,software of SPSS 16.0 was used to calculate its LD50.·RESULTS:The rats of every group showed poisoning reflection.39 rats died,the mortality rate was 55.7%,and 11 rats died in 48 hours,the remaining 28 died in the next 5 days.The LD50 of nickel sulphate in juvenile rats by ip injection was 33.476mg/kg,with the 95% confidence interval of 33.476±1.525mg/kg.·CONCLUSION:The LD50 of SD juvenile rats with ip injection of nickel sulphate is 33.476mg/kg,which is credible.·