The main objective of the present study was to identify chromosome number variation in the progenies from triploid × diploid/tetraploid (3x × 2x/4x) crosses in Lilium to analyze the survival of aneuploid embryos from 3x × 2x/4x crosses and the potential significance of triploid for lily breeding. Two male-sterile autotriploid Asiatic lily cultivars were crossed with four diploid and/or two autotetraploid Asiatic cultivars. The results showed that the fruits of all triploid × diploid/tetraploid (3x × 2x/4x) crosses fully developed, and seedlings were obtained from the 3x × 2x/4x crosses, indicating that male-sterile autotriploid lilies can be used as female parents. Chromosome preparation showed that the progenies of the 3x × 2x/4x are predominantly aneuploid. Based on megasporogenesis, we deduce that the endosperm of 3x × 2x is 7x and that of 3x × 4x is 8x in Lilium and conclude that the aneuploid embryo survival of 3x × 2x/4x in Lilium is the result of the euploid endosperm. Lily is usually propagated by scaling or tissue culture; therefore, aneuploids obtained from triploid × diploid/tetraploid lilies would be a good source for cultivar breeding.