The comparative toxicological researches on crude and processed drugs show that the activating action of Radix Kansui, Radix Achyranthis Bidentatae and Semen Armeniacae Amarum on EBV-EA can be decreased by processing. Processing can also decrease stimulating activity on mouse skin, inhibit tumor-promoting activity in two stage skin tumor promoting test and lapactic effect by Radix Kansui. Meanwhile the pharmacological effects of these drugs can be retained or increased by processing.