The steric effect of the alpha-diimine nickel catalyst on allylcyclohexane (ACH) and vinylcyclohexane (VCH) polymerizations has been studied with the aim of improving the monomer conversion and living fashion. We herein proposed a promising approach to enhancement on alpha-diimine nickel-catalyzed alkenylcyclohexane polymerization by moving steric bulk from the ortho-aryl to the ligand backbone to overcome the steric repulsion between them. A camphyl derived alpha-diimine nickel catalyst with 2,6-dimethylphenyl was successfully used to catalyze living isomerization polymerizations of ACH and VCH. Microstructure analysis of the obtained polymers revealed that ACH and VCH were preferentially inserted into secondary Ni-alkyl species (Ni-CH) in 2,1-insertion fashion followed by precise chain walking to form 1,omega-unit on the main chain. The isolated 1,2-insertion of the alkenylcyclohexane monomers infrequently took place, thus leading to the presence of 2,omega-unit by chain walking and 1,2-unit by direct insertion on the main chain.