The purpose of this research was to clarify the morphological characteristics of foot calli with inflammation. The subjects were 30 diabetic patients with unnoticed foot calli. Inflammation was identified by thermography and ultrasonography as physiological measurement tools. The relationship between morphological characteristics and inflammatory findings was then investigated. Sensitivity, specificity, positive predictive value and negative predictive value of the morphometric characteristics were calculated if they showed significant differences in inflammatory findings. Sixty-three calli were observed in the 30 patients. Ten percent of calli were defined as inflammatory with thermography and ultrasonography. The ratio of patients with sharply-demarcated calli was significantly higher（p=0.016）among those with inflammatory calli. The sensitivity and specificity were 60.0% and 91.1%, respectively, when the demarcation of the callus was used as a morphological indicator of inflammation. We consider that morphological observation focusing on the demarcation of calli may be valuable for the early detection of inflammation.