To provide a norbornene-based compound with good efficiency by using an organopalladium complex stable in air and preservable for a long period of time.

The method of manufacturing a homo-or co-polymer of a norbornene-based compound which uses a multicomponent catalyst formed by mixing the following compound (a) and compound (b), is provided. The palladium complex (a) is expressed by general formula (1) in which R, R1, R2 and R3 are each a monovalent alkyl group or an aryl group, and may be mutually the same or different, and the compound (b) is a salt formed of an anion having no unshared electron pair at the central atom and a counter cation.