The presented thesis is devoted to synthesis of nitrogenous heterocycles on solid support. The first part is focused on solid-phase synthesis of combinatorial arrays of 2H-indazole 1-oxides and their fused derivatives, 3,4-dihydropyrazino[1,2-b]indazoles and their 6-oxides by using split-split methodology. The second part of the work is focused on diversity-oriented synthesis of various nitrogenous heterocycles, such as 1H-imidazoles, 1,5-dihydropyrrol-2-ones, 1H-pyrazin-2-ones, 4,5-dihydro-1,2,5-triazepin-6-ones, morpholin-3-ones, and 2H-isoquinolin-1-ones, from polymer-supported a-acylamino ketones. Chemistry of 2H-indazoles and the other heterocycles is based on different reaction outcomes derived from 2- and 4-nitrobenzenesulfonyl derivatives. Some of prepared heterocycles were submitted for evaluation of biological activity, such as cytotoxic and antimicrobial activity.