The phase state of the catalytic system of Co(naph)2-Al(i-Bu)2Cl was investigated by the Tyndall effect

electronic microscope and super-filtering experiment．The results showed that the colloidal particle size of the Co(naph)2-Al(i-Bu)2Cl catalyst was dispersed in butadiene-contained toluene solvent within the range of nano-scale size．Under the optimum conditions

the diameter of the catalytic particles was from 1 nm to 100 nm and the catalyst belonged to multiphase catalyst．The active sites were located on the surface of the colloidal particles

while the catalyst particles were amorphous．The ratios of catalyst components affected the shape of colloidal particles

among which the colloidal particles of the optimum ratios were small in size

uniformly distributed and with high catalytic activity．This paper summarizes that the characteristic of colloid catalysts is similar to that of homogeneous catalytic system

but the catalytic activity was apparently affected by preparing methods such as component ratios

adding order and aging．It point out that kinetic conditions of colloid catalyst approximates to those of homogeneous system

i．e．in the initial stage of polymerization reaction．the monomer concentration is 102～3 times as great as that of alkylaluminium and the other components．