The potentiation effect of four natural compounds i.e. Oshar and Neem plant extracts, Vertimec and Spinosad biocides to Chlorophacinon anticoagulant toxicity was evaluated against black rat Rattus rattus under laboratory and field conditions. Results showed that when each compound was tested alone in both non-choice and free choice feeding methods, Oshar plant extract was the most effective one followed by Vertimec biocide and Neemix plant extract while Spinosad biocide did not exhibited noticeable effect. Concerning the palatability, the tested compounds could be arranged according to their acceptance in a descending order as follows : Spinosad > Oshar > Vertimec > Neemix. Regarding the potentiation effect, each tested compound was added at level 10 ml/ kg to dlorophacinon bait 0.005%. Oshar plant extract considerably enhanced the toxic effect of Chlorophacinon than Chlorophacinon alone followed by Vertimec and Neemix. On the other hand, Spinosad has no effect on the toxicity of Chlorophacinon. Also, the results which obtained from the field experiments were in complete harmony with the laboratory results as the combination of Chlorophacinon and Oshar gave the highest rate of population reduction against the black rat Rattus rattus followed by Vertimec while the mbdure of Chlorophacinon with Neemix gave the lowest rate.