This paper deals with studies on the dilute solution properties of methyl methacrylateâ��acrylonitrile copolymer of 0.289 mole fraction (mf) of acrylonitrile composition. Markâ��Houwink parameters for this copolymer have been evaluated in acetonitrile (MeCN), 2-butanone (MEK), dimethylformamide (DMF) and Î³-butyrolactone (Î³-BL). The solvent power is found to be in the order of MEK < MeCN < DMF < Î³-BL at 30Â°C. Herein, probably for the first time, the steric factor for the copolymer is found to be lower than that for the parent homopolymers and the excess interaction parameter, Ï�AB is found to be negative. This probably suggests that the units are compatible to each other.