Laboratory studies were applied to investigate the efficiency of three art-'coaguiant rodenticides, Brodifacoum, Chlorophacinone and Warfarin on the both sexes of albino Norway rat, Rattus norvegicus which were fed on either maize and meat or vegetables. 'he obtained results could be summarized in the following :- The results proved that, all three rodenticides induced a considerable emotion in numbers of implantation sites in both left and right horn uterus and t‘ese reduction widely differed according to the rodenticides type. The maximum 'eduction was observed in both cases with percentage of 100% when females were tested with Brodifacoum and Chiorophasinone at 1/10 L090, while minimum 'eduction was noticed when females were feeding on mazie and wheat treated with ariarin at 1110 L030. where the percentage of reduction was 12.5%. On the other “and, the data appeared that the sublethal dose 1!10 LD30 of alt anitcoaguiants "ave non-significant effect on both gestation preiod and weight of fetuses in the two g'oups. But they have a highly significant effect on the mean number of fetuses when females which were feeding on maize and wheat treated with Brodifacoum and Cniorophacinone. Also. the same results were obtained when females fed on .egetable treated with Brodifacoum. In addition, the obtained results cleared that the asbiethal dose 1510 L030 from Brodifacoum in the two cases of feeding have a =:;nit'icantty increase on the mean time of weaning per days. While, there were non— sgnificant increase on the mean time of earning per days with other treatment in two :ases of feeding. Ate-o, there was non-signifact increase on the mean of opening eyes in ail treatment with the three rodenticides in two groups of feeding.