Basic ionic liquid catalyzed synthesis of various pyrazolo [3, 4-b] pyridines were synthesized by cyclocondensation of 5-amino-3 aryl -1-H phenylpyrazoles, p-substituted benzoylacetonitriles and some aryl aldehydes by using basic ionic liquid, [bmIm]OH. It acts as a base catalyst. Comparative study of triethylamine and [bmIm]OH. and ammonium acetate was studied .Reusability of catalyst with good yields under green reaction conditions is the salient feature of this synthetic method.