1. The aim of the present study was the evaluation of human gastric ulcer healing and intractability from the viewpoint of connective tissue components. 2. Based on investigations of clinical status, we divided 78 patients with a gastric ulcer into three groups. All patients underwent gastrectomy and group I consisted of 17 patients operated on for bleeding or perforation, group II consisted of 37 patients operated on for an accompanying gastric carcinoma and group III consisted of 24 patients operated on for ulcer intractability. 3. We evaluated, in resected specimens, angiogenesis by Azan-Mallory staining and fibroplasia by applying proliferating cell nuclear antigen (PCNA) immunostaining. The inflammatory grade and fibrosis at the ulcer base were also evaluated by haematoxylin-eosin and Azan-Mallory staining. 4. Microvessel counts in group III were significantly lower than those in group I and II (P < 0.05). The PCNA labelling index of fibroblasts in group III was significantly lower than that in groups I and II (P < 0.05). The inflammatory grade was severe and fibrosis was excessive in group III. 5. From these results, it is suggested that the reduced angiogenesis and decline in fibrous cell proliferation are important factors contributing to gastric ulcer intractability.