The palladium(0)-catalyzed polyaddition of bifunctional vinyloxiranes [1,4-bis(2-vinylepoxyethyl)benzene (1a) and 1,4-bis(1-methyl-2-vinylepoxyethyl)benzene (1b)] with 1,3-dicarbonyl compounds [methyl acetoacetate (4), dimethyl malonate (6), and Meldrum's acid (8)] was investigated under various conditions. The polyaddition of 1 with 4 was carried out in tetrahydrofuran with phosphine ligands such as PPh3 and 1,2-bis(diphenylphosphino)ethane (dppe). Polymers having hydroxy, ketone, and ester groups in the side groups (5) were obtained in good yields despite the kinds of ligands employed. The number-average molecular weight value of 5b was higher than that of 5a. The polyaddition of 1b and 6 was affected by the kinds of ligands employed. The corresponding polymer 7b was not obtained when PPh3 and 1,2-bis(diphenylphosphino)ferrocene were used. The polyaddition was carried out with dppe as the ligand and gave polymer 7b in a good yield. The molecular weight of the polymer obtained from 1b and 8 was much higher than those of polymers 5b and 7b. The polyaddition with Pd-2(dba)(3). CHCl3/dppe as a catalyst (where dba is dibenzylideneacetone) produced polymer 9b in a 92% yield (number-average molecular weight = 45,600). The stereochemistries of all the obtained polymers were confirmed as an E configuration by the coupling constant of the vinyl proton.