Characterization of soluble and insoluble polymers obtained by radical polymerization of L-methyl lactate methacrylate (MLAM) with 2,2'-azabisisobutyronitrile was performed. ^1H-NMR spectra of the soluble polymer were measured in CDCl_3 at 270 MHz. The peak due to α-methyl proton of the polymer was complexly split indicating the polymer was consisted in atactic structure. Viscosity of the polymer solution was measured in tetrahydrofuran (THF). The [η] in THF solution was much greater than that in toluene. Soften points of the soluble and insoluble polymers was measured. The soften point of the insoluble polymer was 90℃ which was 10℃ higher than that of the soluble polymer. Transesterification reaction of the insoluble polymer obtained from MLAM was carried out in methanol with potassium hydroxide. Soluble polymer was obtained by the reaction even in low yield. Molecular weight of the soluble polymer was somewhat high indicating the molecular weight of the insoluble polymer was quite high.