Abstract: There are, though rare, some data on acute toxicity of potassium permanganate being used in clinic for lavage of stomack after ingestion of alkaloids and otherorganic poisons. But the attributing factors are still vague and ambiguous. In order to make it clear, the acute toxicity of potassium permanate and the combination of potassium permanganate and scopolamine hydrobromide, a selected alka loide, were experimented on mouse.As a result, the LD_(50) of potassium permanganate, scopolamine hydrobromide and their combination were 986, 957 and 1177 mg/kg, LD_5 were 375, 355 and 467 mg/kg; and the time of death in 95% confidence ranged from 1.92 hr. to 5.6 days, 0.01 to 1.09 hr. and 0.5 hr. to 5.8 days repectively.According to the results, the toxicity of potassium permanganate was medium The combination, as expected combined value of LD_(50) was 971 mg/kg and the measured one, 1177 mg/kg, thus the k=1.21, was recognised as an additional joint action. And, as to the types of time of death, scopolamine hydrobromide showed very quick, potassium permanganate delayed, and the combination held the characteristics of both of them.It is concluded that when the potassium permanganate and the scopolamixe hydrobromide have been uptaked, the con tributing factors of poisonning and/or even death, are both of them, and the concentration of potassium permanganate solution for lavage of the stomack should be under 1/5000.