Abstract: The purpose of this experiment was to investigate the histochemical property of the mast cells in the digestive tract tissue of Anguilla Japonica and observe the heterogeneity of cytoplasm granules of mast cells.This experiment used improved toluidine blue staining(MTB),Alcian blue Safranin O staining(AB/SO),methyl green-Pyronine staining(MG-P) and AzureⅡ-Eosin-Wright mixture staining.The mast cells in the digestive tract of A.Japonica were displayed better by Alcian blue Safranin O staining.The effect of methyl green-Pyronine staining (MG-P) and AzureⅡ-Eosin-Wright mixture staining was generic,and few mast cells were dyed.Even the improved toluidine blue staining couldn’t show the mast cells.Small amount of mast cells mostly distributed in connective tissues of lamina propria and under mucosa epithelium in mucous layer of esophagus,stomach and intestine. While less lied in connective tissues of submucosa,and intended to be around blood vessels.The shapes of the mast cells which were small in size were circular,ellipse,spindle and irregular.The effect of Alcian blue Safranin O staining was the best,which was applicable to identification of the mast cell of A.Japonica.The improved toluidine blue staining was not applicable.