AbstractSyndiotactic poly(methyl methacrylate) (st‐PMMA) macromonomer having methacryloyl end group was prepared from st‐PMMA living anion and separated into uniform macromonomers by means of supercritical fluid chromatography. A uniform macromonomer with the degree of polymerization of 32 was polymerized radically in benzene at 60°C. The uniform dimer, trimer and tetramer of the uniform macromonomer were isolated from the polymerization product by means of gel‐permeation chromatography (GPC). The intrinsic viscosity ([η]) in tetrahydrofuran of these uniform comblike polymers was determined by GPC/differential viscometric analysis. The plot of logarithmic [η]against logarithmic molecular weight indicated that the trimer and tetramer assume a little shrinking molecular shape as compared with the unimer a