Dynamic surface properties of aqueous solutions of cationic polyelectrolytes poly(hexylmethyldiallylammonium chloride) (PHMDAAC) and poly(butylmethyldiallylammonium chloride) (PBMDAAC) differ significantly from the properties of the solutions of other charged homopolymers, for example, sodium poly(sterenesulfonate) (PSS) and poly(dimethyldiallylammonium chloride) (PDMDAAC). At the same time, the obtained results are in agreement with the predictions of the theory of the dilational surface viscoelasticity of polymer solutions. The dynamic surface elasticity of PHMDAAC solutions increases monotonically with the surface age up to about 30 mN/m while the increase of the solution ionic strength results in non-monotonic kinetic dependencies and in low values (<5 mN/m) of the surface elasticity close to equilibrium. The surface activity of PBMDAAC is much lower and the deviations of the surface elasticity from zero exceed error limits only slightly in the investigated concentration range (≤0.2 wt%).