Living polymerization method

A living polymerization method for polymerizing at least one monomer selected from the group consisting of (meth)acrylic acid esters, epoxides and lactones using a metal porphyrin complex as a polymerization initiator, wherein said metal porphyrin complex has a central metal site occupied by a metal selected from the group consisting of magnesium, aluminum, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, ruthenium, rhodium, palladium and cadmium, and said living polymerization is performed using as a cocatalyst at least one organic aluminum compound selected from the group consisting of compounds represented by general formulae (I) and (II) below:

• ##STR12## wherein R.sub.1 represents a halogen atom, a C.sub.1 -C.sub.8 alkyl group, a C.sub.1 -C.sub.8 haloalkyl group, a C.sub.2 -C.sub.8 alkenyl group, a C.sub.6 -C.sub.14 aryl group or a C.sub.7 -C.sub.20 aralkyl group;
• R.sub.2, R.sub.4, R.sub.6, R.sub.7, R.sub.9 and R.sub.11 independently represent a hydrogen atom, a halogen atom, a C.sub.1 -C.sub.20 alkyl group, C.sub.1 -C.sub.20 alkoxy group, or a C.sub.6 -C.sub.14 aryl group;
• R.sub.3, R.sub.5, R.sub.8 and R.sub.10 independently represent a hydrogen atom, or a halogen atom;
• Z.sub.1 and Z.sub.2 independently represent a simple chemical bond, ##STR13## where, R.sub.12 and R.sub.13 independently represent a hydrogen atom, a C.sub.1 -C.sub.20 alkyl group or a C.sub.6 -C.sub.14 aryl group;
• R.sub.14, R.sub.15, R.sub.16, R.sub.17, R.sub.18, R.sub.19, R.sub.20, R.sub.22 and R.sub.23 independently represent a hydrogen atom, a halogen atom, a C.sub.1 -C.sub.20 alkyl group, or a C.sub.1 -C.sub.20 alkoxy group;
• and
• Z.sub.3 and Z.sub.4 independently represent chemical bond, ##STR14## where, R.sub.12 and R.sub.13 have the same meanings as defined above.