In the present report the result of investigation of combined operating of propyl clone of Arminum is esteemed at effect on different intensity levels (LD, ED, Relatively Safe Level of Compound), with three-orthocresylphosphate and chlorophose in experience on white mice. The tendency of more expressed potentiation of toxic effect is detected at low levels of toxicant effect. Based on the dates of literature and the mathirials of the inner investigation, the expediency of the count toxicometric and statistical parameters received by a probit-method at a 5% level responses of the bioanswer is routined at a quantitative assessment of effects of combined operating of xenobiotics on low levels of effect.