Abstract: This study deals with pure Iraqi red beet juice which is extracted mechanically into two states, the pure anthocyanin juice and its solid state obtained by evaporation the pure anthocyanin juice until obtained the pure solid anthocyanin. By boiling the juice at 102°C and heating the solid at 110°C both of them show dimerization product which are confirmed from the weight of liberated water and the degree of polymerization is 2 (dimer formation).The pure solid anthocyanin and dimer anthocyanin (by heating and boiling) added to biopolymers (poly vinyl alcohol, poly methyl methacrylate, starch and cellulose)and noticed that this pigment effected on the glass transition temperature, density and hardness of biopolymers.