Copolymers of N-vinylpyrrolidone and 2-methyl-5-vinylpyridine with various ratios of monomer units and molecular weights have been synthesized by radical copolymerization using injection method. The ratio of monomer units was determined by nonaqueos potentiometric titration and 13 С NMR methods. The viscosity-average molecular weight of copolymers containing 35 - 39 mol % of 2-methyl-5-vinylpyridine units is within 15.2 - 27.6 kDa. The copolymers with a content of 2-methyl-5-vinylpyridine units up to 75 + 5 mol % exhibit good solubility in water.