Abstract: Model of chickens with deuto-chronicity different level of AI（Aluminium intoxication） toxic was established by continuous peritoneal injection of fixed volume and different concentration gradient aluminium trichloride. The growth index of spleen and bursa of Fabricius were detected，and the structure of them were observed by using light and electron microscope.The results showed that:(1)The growth index of spleen and bursa of Fabricius were significantly lower in chickens with AI toxic than that in the control ones and there were dose-effect relationship with aluminium trichloride.(2)Histopathologically，middle and low dose group had no apparent pathological change，in high dose group，spleen presented changes of apoptosis morphology and germinal center of folliculus lymphaticus in bursa of Fabricius hyperplasyed.(3)Ultrastructurally，low dose group had no apparently pathological change，in high dose group，karyolemma broke，mitochondria swelled，cristae broke or disappeared，rough endoplasmic reticulums dilated，cisternas widen，confluenced to vacuole and presented typical mark shape of apoptosis in lymphocyte of spleen and karyolemma broke，caryolysised，myelin bodys appeared，cell organs of intracytoplasm decreased obviously in lymphocyte of bursa of Fabricius.The results indicated that AI toxic greatly inhibited the development of spleen and bursa of Fabricius，and caused obvious pathological injury in these tissues.