The autoimmune antiserum specific to pellicle of human metaphasic chromosomes from a lupus patient was used to stain metaphasic chromosome Vicia faba by means of indirect immunoflourescence method. It was found that the pellicles of vicia metaphasic chromosomes was positively stained. The antigen of Vicia faba recognized by the antiserum was also examined by PAGE of total cell lysate and western blotting.