RESUMEN
The lymphonodus cervicothoracious and lumbaris of 19 Pekin ducks were studied using the histological methods. The lymph nodes are consisted of the capsule, loose areas, and dense areas. There are lymphatic tissue cords, connective tissue cords and intercord lymph sinus and lymphatic nodules also in the loose areas. The dense area are consisted of lymphatic nodules and mass of lymphoid cells. The lymphatic nodules are irregularly distributed and no germinal centers. The lymph sinuses may be classified into the central sinus and peripheral sinus. The latter may be subdivided into subcapsule sinus, paralymphonodular sinus and the intercord lymph sinus. There are reticular cells in the intercord lymph sinus. No true trabeculae are present but there are many blood vessels and nerves in the lymph nodules.