Radical copolymerization of N-isopropylacrylamide (NIPA) with N-vinyl-2-pyrrolidone (VP) were carried out with 2,2'-azobisisobutyronitrile (AIBN) as an intiator in NW-dimethylformamide solution at 65 degrees C under nitrogen atmosphere. Compositon of the copolymers synthesized in a wide range of monomer feed ratios were determined by FTIR and H-1 (C-13) NMR-DEPT-135 spectroscopy. The monomer reactivity ratios were determined by Fineman-Ross, Kelen-Tudos and non-linear regression methods. It was observed that the studied monomer pair has some tendency to alternation in the chosen monomer feed ratios due to fort-nation of intermolecular interaction through H-bonding and N -> 0 = C coordination. The synthesized poly(NIPA-co-VP)s show temperature sensitivity (T-s), higher glass-transiton temperature (T-g), thermal stability, polyelectrolyte and stimuli-responsive (temperature- and pH-sensitive) behavior and can be attributed to the class of bioengineering functional copolymers useful for application in various gene- and bioengineering processes, drug delivery systems and biomacromolecule conjugations.