Some two‐, three‐ and four‐component phenolic copolymers have been characterized, and mixed in definite stoichiometric proportions. The total amount of acidic and basic functional groups in a given weight of the copolymer mixture have been calculated from the characteristic parameters of the polymer components. Analysis of these copolymer mixtures by electrometric titration techniques revealed an excellent correlation between the calculated and observed values of functional groups.