Influences of culture media and sucrose concentrations on plant regeneration from Easter lily (Lilium longiflorum L. cv. Ace) ovary tissues were investigated. Pistils excised from unopened flower buds (3-5 cm long) were sectioned and cultured on either B-5 medium or Murashige and Skoog (MS) medium containing 2%, 5%, or 10% sucrose, with 1 mg·L-1 2,4-D and 2 mg·L-1 BA. Callus formation was most prolific on MS medium containing 5% sucrose. Shoot differentiation was higher on MS medium than on B-5 medium. Rooted plants were transferred into soil medium and grown in a greenhouse. Root tip smears showed that 35% of the regenerated plants showed a variation in chromosome numbers from 10 to 25 per cell, while the rest of the regenerants showed the normal 2n = 2x = 24 chromosomes per cell. The mixoploid condition also existed in different root cells of the same regenerated plant. Chemical names used: 2,4-dichlorophenoxyacetic acid (2,4-D); 6-benzylaminopurine (BA).