We have investigated Bi2O3-Eu2O3 binary system by doping with Eu2O3 in the composition range from I to 10 mole% via solid state reactions and succeeded to stabilize beta-Bi2O3 phase which is metastable when pure. Stability of beta-Bi2O3 polymorph was influenced by heat treatment temperature. Tetragonal type solid solution was obtained in 3-6 mole% addition range when annealed at 750degreesC and the range was 2-7 mole% when annealed at 800degreesC. We have also carried out investigations on lattice parameters, microstructural properties and elemental compositions of this beta type solid solution for each doping ratio. Lattice parameters increased with amount of Eu2O3 addition. Our experimental observations strongly suggested that oxygen deficiency type non-stoichiometry is present in doped beta type solid solutions.