MC nylon was synthesized under the anionic polymerization of caprolactam to investigate the influence of the amount of catalyst and activator on the polymerization time and the crystalinity. The results show that with the increase of the amount of catalyst, the polymerization time shortens notably while the crystallinity increases at first and then decreases, that as the amount of cativator increases, the polymerization time shortens, and that the crystallinity increases at first and then decreases slightly.