Abstract: Cytological observation, was made to dectect chromosome aberrations in hybrid-embryo-derived calli as well as in somatic cells and PMC's of regenera ted plants of barley(2n = 14)cv. Ant-13 × common wheat(2n = 42)cv. Chinese Spring. The results reveal that mixoploidy exists throughout the whole process of the above-mentioned stages. However, as the differentiation and develop ment proceed, mixoploidy level become less and less, and the proportion of di haploid cells(2n = 28)become greater and greater. Abnormality of chromosome behavior occurs from premeiotic mitosis until various stages in meiosis, thus resulting in pollen abortion and self-sterility of the hybrid plants. Pollen abortion occurs at the uninuclear stage of PMC's.