Various staining and fixation methods have been used to demonstrate the mast cell, but there is a controversy on the density of mast cells observed by these methods. We observed different distribution and the mast cell density in 15 palatine tonsils obtained by tonsillectomy. The specimens were stained with toluidine blue, azure A, astra blue, or alcian blue-safranin method after being fixed with 10% buffered formalin or Carnoy's solution. The results were as follows. 1) A number of mast cells were observed in subepithelial and internodular areas but not in epithelial layer or the germinal center of lymph nodules of the palatine tonsil. 2) The mast cell density in the specimens fixed in Carnoy's solution is significantly increased compared to that of the specimens fixed in formalin. 3) The mast cell density in the specimens stained with astra blue is significantly increased compared to that of the specimens stained with touidine blue, azure A, or alcian blue-saframin. Therefore, we concluded that Carnoy's fixing solution and the astra blue staining procedure is the best method to demonstrate the mast cells to the human palatine tonsil.