Improved methods were made to count the absolute numbers of basophils and eosinophils by adding phosphate buffer to Kovacs staining fluid. The improved method has following advantages. 1) Both basophil and eosinophil leucocytes can be easily recognized and identified simultaneously. 2) The staining fluid is stable for more than one year at room temperature. 3) Within two hours after filling a pipette, precipittates or ghost cells still do not appear. 4) This method is simple and convenient for the routine examination like calculation of peripheral leucocytes. Changes of basophil leucocytes in the peripheral blood in various diseases were investigated with above described method. Basophilia was shown in allergic rhinitis, bronchial asthma, parasite infection, idiopathic thrombocytopenic purpura, acquired hemolytic anemia, hypothyroidism, iron deficiency anemia, chronic myelogenous leukemia and Addisons disease.