Novel homogeneous micro-scaled hollow polyelectrolyte capsules were prepared by using alternate adsorption of poly-dimethyl-diallyl-ammonium chloride (PDMDAAC) and cellulose sulfate sodium (NaCS) on calcium carbonate (CaCO 3 ) template particles. The CaCO 3 particles with various shapes were prepared by the reaction of potassium carbonate (K 2 CO 3 ) with calcium chloride (CaCl 2 ) in the presence of carboxylmethyl cellulose (CMC). The results showed that at a CMC concentration of 0.5g/L, smooth spherical CaCO 3 particles were obtained, which were used as core templates. Thereafter four bilayers of PDMDAAC and NaCS polymer film were deposited on the CaCO 3 cores. The film buildup was characterized by (i) microelectrophoresis; (ii) scanning electron microscopy (SEM); and (iii) thermogravimetric analysis (TGA). Hollow capsules were then prepared by exposing the coated CaCO 3 particles to EDTA-Na. Finally the molecular weight cut-off (MWCO) of the microcapsules was determined by exposing the microcapsules to the E. coli cell lysate.