Sawada's urinary pyruvic acid reaction, which is known as indirect diagnostic method of Vit. B(1) deficiency, is widely applicated in various medical disorders, but in my researches in dermatologic area I could not find of this reaction. By applicating Sawada's reaction in dermatodes, following results were obtained: 1) In 66 cases of 115 patients, this reaction appeared positive (57.4%) i. e., about 20% higher than normal persons (36.0%). Showing positivity in main diseases. In eczema chronicum 75%, dermatitis acuta 71.4%, ephelides 60.0%, chloasma 57.4%, urticaria and erythema induratum Bazin 50.0% each. alopecia areata 42.8%, acne vulgaris 37.5%, appeared positive. while in psoriasis vulgaris and trichophytia only 25.0% appeared positive. 2) As liver function tests, Takata's reaction, Hepatosulphalein method and urobilinogen reaction in urine were taken and in most of the cases in which Sawada's reaction appeared negative, these 3 reactions were also negative, but when Sawada's reaction appeared positive, these 3 reactions appeared positive only in a few case. therefore the deficiency of liver function can not be presumed from the positive appearance of this reaction. Determining the liver function from the previous 3 reactions, in the relation between the liver function and Sawada's reaction, 80.0% of the cases with liver dysfunction showed positive reaction of this test. 3) Determining the relation between the blood level of Vit. B(1) and Sawada's reaction, the average of the blood level of Vit. B(1) in the negative cases of this reaction was 7.49γ%. and that of the positive cases was 5.57γ%, and definite difference between them could be observed. Classifying the results of the blood level of Vit. B(1) in two groups, i.e., below 6.0γ% as deficiency and above 6.0γ% as normal value, in the normal cases 58.33% appeared negative in Sawada's reaction, therefore it could not be conclunded that in the cases which the blood level of Vit. B(1) appears normal, Sawada's reaction appears negative. 4) 82.35% of the cases in which Sawada's reaction appeared negative, showed normal blood level of Vit. B(1), while only in the half of the positive cases I found this level below 6.0γ%. So when we apply this reaction in clinical examination, it is misleading to determine Vit. B(1) deficiency by the positive appearance of this reaction.