A series of nine poly(2-deoxy-2-methacrylamido glucopyranose)-b- poly(methacrylate amine) diblock copolycations has been synthesized as new colloidally stable polynucleotide vehicles. The cationic block was varied in length and in the degree of methyl group substitution (secondary, tertiary, quaternary) on the pendant amine in an effort to optimize the structure and activity for plasmid DNA (pDNA) delivery. Upon a thorough kinetic study of polymerization for each polymer, the glycopolymers were prepared with well-controlled Mn and Crossed D sign. The binding and colloidal stability of the polymer-pDNA nanocomplexes at different N/P ratios and in biological media have been investigated using gel electrophoresis and light scattering techniques. The toxicity and transfection efficiency of the polyplexes have been evaluated with Hep G2 (human liver hepatocellular carcinoma) cells; several polymers displayed excellent delivery and toxicity profiles justifying their further development for in vivo gene therapy.