In order to study the relation between backache and B(1) - hypovitaminosis in japanese farmers Sawada's pyruvic acid reaction in urine was tested in 185 patients of variable disorders including 68 cases without backache. Sawada's reaction proved to have a significant correlation between Miyaji's test of liver function. So the clinically liver injured patients and Miyaji positive cases were excluded from Sawada positive cases. And the relation between the remaining Sawada positive cases and backache was put to X(2) test. But no significant relation was proved between them. Many cases of backache were observed among the patients with gastro-duodenal diseases, such as peptic ulcer and cholecystopathy. But no significant relation was proved between the positive Sawada's reaction and the complaint of backache in the patients. Backache was often seen among the patients with ascariasis or ankylostomiasis too. But no significant relation was established between the complaint and positive Sawada's reaction after all.