The purpose of this study was to investigate the effect of vitamin B6 deficiency on the concentration of energy metabolite in streptozotocin-induced diabetic rats. Thirty rats were fed a vitamin B6 deficient diet(-B6) or a control diet(+B6) for 5 weeks and then subdivided into 3 groups respectively ; base group, one day diabetic group and three day diabetic group. Diabetes of rats were induced by streptozotocin injection into the tail vein. Glucose, glycogen, protein, alanine, triglyceride and free fatty acids were compared in plasma, liver skeletal muscle of rats. Also, the total urinary nitrogen and glucose excretion were compared. Compared with +B6 rats, the increase of plasma glucose in -B6 rats due to the diabetes was smaller. After diabetes was induced, the level of plasma alamine was not changed in -B6 rats while increased significantly(p<0.05) in +B6 rats. The increase of urinary nitrogen excretion was smaller and the increase of muscle protein was larger in -B6 rats at the first day diabetes was induced. The levels of plasma free fatty acid and liver triglyceride were significantly (p<0.05) higher in -B6 rats after diabetes was induced. These results suggest that vitamin B6 deficiency may impair the adaptation of animals to the energy metabolism related due to a decrease of the body protein catabolism of fatty acid oxidation in diabetes and aggravate fatty liver which is one of the chronic complications of diabetes.