Objective: To establish the transplanted leukemia severe combined immunodeficiency(SCID) mouse model and to explore the biological action of human leukemic cells in SCID mice.Methods: 5×106～1×107 K562 cells were inoculated into the abdominal cavity or vein of SCID mice.Immunocytochemistry

RT-PCR

flow cytometry and histopathology were used to detect the leukemic cells in the peripheral blood

bone marrow

liver and spleen of SCID mice.Results: K562 cells could be transplanted into SCID mice through abdominal cavity or vein

and leukemia animal model was successfully established.3 weeks after transplantation

the leukemia cells could be found in the peripheral blood

The proliferation phase cells in the liver and spleen reached 40.11% and 41.66% respectively.In the terminal stage

the CD13+ cells accounted for 10.15% of bone marrow cells in model animal.The DQαand ABL-BCR genes could be detected after injection of K562 cells

and 3 to 4 weeks after injection

the leukemic cells spread to the liver

spleen

kidney

bone marrow

and so on.Conclusion: The leukemia animal model could be successfully established by transplanting K562 cells into SCID mice.Positive rate of CD13 might be used as the index of tumor cells infiltration.