Abstract: Oil radish(2n=18,nine chromosomes were named as a-i) carry the resistance gene against the beet cyst nematode(BCN) Heterodera schachtii. Additional chromosome lines of rape for each segregated a-i were obtained.【Objective】Study on which chromosome of oil radish carry the resistance gene against BCN, and the stability of oil radish chromosomes in rape-radish addition lines. 【Method】Self-pollinated progeny F2 of nine rape-radish chromosome addition lines were tested by specific chromosomal molecular markers and fluorescence in situ hybridization (FISH). Those F2 plants were cultured in box and inoculated J2 larvae suspension of Heterodera schachtii. Then the number of cysts on plant roots were investigated 42 days after inoculation.【Result】They showed that the stability of additional oil radish chromosomes in rape is different. There were double additional chromosomes in each tested plant of rape-radish addition lines a, d, e, g, or i. In the rest addition lines, some plants carried additional radish chromosomes, however, some plants have not additional chromosome. Further experiment by FISH confirmed that the stable lines carried 2 additional chromosomes in each tested plant and the unstable lines have 2,1 or 0 additional chromosome(s) in different tested plants. After inoculated J2 larvae suspension of BCN, it shows that the plants of the DD addition line resistant to the BCN, but the other lines were susceptible. 【Conclusion】The hereditary stability of additional chromosomes in rape depend on different chromosomes of oil radish. And the resistance gene was located on “d ” chromosome of oil radish.