Shoot regeneration ability from in vitro leaf explants of different ploidy clones which were derived from the same diploid cultivar of pear (Pyrus communis L.) by colchicine treatment was examined. The regeneration rates of neopolyploids were significantly lower than that of diploid control. Regeneration rates among different neopolyploid clones were significantly different. Triploid ‘3x-3’ and tetraploid ‘4x-4’ failed to regenerate. These results revealed that the decrease of regeneration ability or loss of totipotency was related to the polyploidization.