Abstract: The FMD antigenic-determinant fused gene (O21-O14 -A21-HbcAg) was introduced into lettuce (Lactuca sativa var. capatata) by co-culturing excised cotyledon explants with Agrobacterium tumefaciens. The best transformation efficiency was obtained on co-culture with the selective medium S2 (MS + 1.5 mg.L-1 6-BA + 0.2 mg.L-1 IAA + 500 mg.L-1 Cb) containing 20 mg. L-1 hygromycin. Roots were induced on S3 (1/2 MS + 20 mg.L-1 Hyg). Integration of FMD antigenic-determinant fused gene O21-O14 -A21-HBcAg into the genome of lettuce plants was confirmed by PCR and Southern blotting analysis. Expression of the fused gene at the transcriptional level was shown by RT-PCR.