Abstract: Wild Oryza species posses valuable characteristics that, if introduced intorice, can increase both the resistance to pests and tolerance to environmental stresses.Protoplasts of four wild rice species (Oryza australiensis, O. granulata,O. latifolia and O. ridleyi) were fused with those of a cultivated rice Taipei 309. Both protolasts fromcell suspension and leaves were used. IOA and y-ray irradiation treatments were applied before fusion to form complementary selection system. Total 6.28×10⁷ protoplasts of wild rices were electrofused from which 4364 calli were obtained and 490 plants were regenerated. Different rates of colony formation and plant regeneration were observed,probably as a result of the compatiblllty between the wild and cultivated genomes. Thehybrids were confirmed by morphology assessments and RAPD analysis.