SEBS is used as building blocks to fabricate size controllable polypyrrole (PPy) capsules. Polypyrrole shells grow on the surfaces of the size controllable oxidant submicroparticles dispersed in the solution cast film of a SEBS copolymer by vapor phase polymerization. After washing in ethanol, PPy sub-microcapsules dispersed in a SEBS matrix are obtained. This technique shows advantages of lower cost and less pollution, as compared with the gold-template method reported in the literature.