Abstract: Chinese Cabbage–Cabbage alien addition line AC8 was radiated to obtain M1 plants. Doubled haploid lines were further obtained by microcspores culture for backcross descendants of M1. Two hundred and eighty-six specific InDel molecular markers linked to cabbage linkage group were used for detecting the DH lines. Combining with cytology observation，the translocation line AT8-1 of Chinese cabbage was identified. AT8-1 was selfed，backcrossed and hydridized，then their offsprings were identified by the specific makers. Results showed that the translocation fragment form cabbage was instability，the ratio of keeping entire exogenous fragment in selfing progenies，one backcross progeny and two hybridization progenies were 61.1%，26.3%，24.2% and 30.0%，respectively. In all progeny individuals，none translocation plant was found with smaller fragments than in AT8-1.

Key words: Chinese cabbage, cabbage, translocation line, genetic stability