Abstract: The microtacticity of seven poly (n-alkyl methacrylates)prepared from radical polymerization has been determined by ~(13)C NMR. High syndiotactic stereoregularity was observed and the ester size showed little influence on the microtacticity of the chains. This phenomenon may be related to the structure of the terminal radical formed in the propagation reaction in free-radical polymerization. A preliminary explanation has been given.