The interaction of the nucleosides and nucleic acid bases with ubiquirone, 0 were studied experimentally using coulometric technique with constant potential. The nucleic acid bases and nucleosides used are adenine, adenosine, cytosine, cytidine and uracil. From our work it's found the Ub,0 forms stable solution in aquaious phosphate buffer, the number of reduction electrons are constant (2.00e). even after 360 hours after solution formation. It's found that the reduction of Ub,O - nucleic acid base, or nudeoside mixtures is reversible after 2 hours of addition and deviates from reversibility after mixing for 6 to 48 hours, but after 72 hours or more, the reduction process was nonreversible. These results show that secondary intermediates were involved in the reaction and different existed in the solution The results show that the molar ratio of base or nucieroside to Ub,0 does not seem the influence on the of electrons that measured chronometrically. Our conclusion that the Ub,0 form complexes with nucleic acid base nudeoside the formation of which are slow processes due to the conversion from reversible to nonreversible behavior which requires period. Our results are fitted with those results that were found by et-al(59-60).