About biological affecting of flavonoids on animal organisms is known less, thus we selected flavonoids, flavanones and flavones, and their glycosides, which were examined as potential inducers of cytochrome(s) P450 when administrated by gavages into experimental male rats. The study was focused on induction of CYP1A1, the major cytochrome P450 involved in carcinogen activation. The data obtained demonstrate the necessity of taking into account not only ability of flavonoids to bind to Ah receptor (induction factor) but also to concentrate on their distribution and metabolism (including colon microflora) in the body. After that we examined certain flavonoids as potential inducers of cytochrome P450, we wanted to suggest and optimize suitable electrochemical technique for determination of selected flavonoids (quercetin, quercitrin, rutin, chrysin and diosmin) in body liquids. For these purposes, we selected square wave voltammetry using carbon paste electrode.