To synthesize novel phospholipid polymers by polycondensed, 1,3-dichloroisopropyl phosphorylcholine (DCPC) was synthesized as a new monomer. The DCPC was reacted with 1,4-dibromobutane in the presence of potassium carbonate, and polycarbonates having phosphorylcholine group were obtained with changing in the mole fraction of DCPC unit. The number averaged molecular weight (Mn) of the polycarbonate determined by gel-permeation chromatography was in the range between 4 x 10(3) - 1 x 10(4) g . mol(-1). The polycarbonate containing 30 mol-% of DCPC units was dissolved in water. The surface tension measurement of an aqueous solution containing the polycarbonate indicated the formation of a polymer associate when the concentration of the polycarbonate was higher than 5.0 x 10(-3) g/dL.