The rate-limiting enzyme to catabolize 5-fluorouracil (5-FU) is dihydropyrimidine dehydrogenase (DPD), which expression in cancerous tissue is reported to have a relation with anti-tumor effect for 5-FU. In this study, we evaluated the immunohistochemical expression in gastric cancer using two different kinds of anti-human DPD antibody, KM1915 and KM1919. However, recognition of both antibody was mimetic in human gastric cancer, and strong expression of DPD was observed in the interstitial tissue when using KM1919. There is a positive relationship between immunohistochemical expression by KM1915 and mRNA expression in human gastric cancer. Immunohistochemical study with KM1915 might be a clinically useful method to evaluate the expression of DPD in paraffin-embedded materials.