Ten dogs were divided into 2 groups and absolute ethanol was injected into the renal artery and its branches respectively. The kidneys injected were resected by stages and examined pathologically. The results showed that coagulative necrosis developed in the renal artery and kidney itself. In the group whose branches of the renal artery were injected there was a clear demarcation line between the necro-tic and the normal areas. The thrombus formed secondary to necrosis might worsen the blockage of the renal artery. The clinical observations on the renal artery injected with absolute ethanol in 15 cases showed that the method of absolute ethanol injection was better than any other methods or drugs for the renal artery. The injection was safe, convenient and more favourable to the prevention of the spread of cancer cells.