We quantitatively studied the effects of counter anions and solvents on the catalytic activity of thiazolium due to the completion of the formose reaction using the highly active immobilized catalyst. The relation between counter anions and the catalytic activity of thiazolium was represented very well by the electron donor constant and the basic constant of the anions, The solvent effect was represented by the individual solvent parameter, In this study, it was given an important information about the effects of the counter anion and the solvent on the reaction using an immobilized thiazolium catalyst.