Abstract: Olaquindox,arsanilic acid,and oxytetracycline are three common kinds of veterinary drugs and feed additives.Their eco-toxicological effects on zebrafish(Brachydanio rerio)and carp(Cyprinus carpio)were studied through acute toxicity test,and embryo test of zebrafish,and single kidney cell gel electrophoresis test(SCGE)in vivo of carp.Results show that acute toxicities of the three substances were not significant at concentrations of the ecological sense;olaquindox and arsanilicacid showed a significant teratogenic effect on the embryo,olaquindox and oxytetracycline could bring about obvious great DNA damage to carp kidney cells in vivo and have potential genotoxicity to fish.