Remarks on polyphenolic compounds has been arisen since past few years. the flavonoids appears to be the important groups of compounds with their capability to inhibit DNA damage, lipid peroxidation, to quench free radicals and, at least, anticarcinogenic and antiproliferative effects. On the other hand, their mechanism of action is still unexplained. Apigenin and luteolin are the most wide-spread flavones and they exhibited to be useful in chemoprevention. UV spectrometric and DC polarographic studies on these two compounds have been carried out with regard to changing pH. The most significant changes were observed at basic pH. These results could aid to elucidation of their mechanism of action as pH is one of the important factors for bioprocesses passing in living organisms.