The anionic polymerization behavior of 4-methyl-4-phenyl-1-buten-3-yne (2) was investigated to get information on the effect of substituent at the 2-position. The polymerization of 2 did not proceed in tetrahydrofuran at -78degreesC by lithium initiators, while sodium initiators can conduct the polymerization smoothly to give polymers consisting of a specific 1,2-polymerized unit. The living nature of the polymerization of 2 by diphenylmethylsodium was supported by the post-polymerizaton experiment.