In order to introduce the Canine Behavioral Assessment and Research Questionnaire (C-BARQ), which is a standardized system for evaluating the behavioral traits of dogs, to Japan, where the environment with respect to dog ownership is thought to differ from those of the United States and Europe, we compared demographic information on dogs in the United States and Japan and examined whether similar factors could be extracted from both countries using questionnaire items of the C-BARQ. The C-BARQ was completed by 11,410, and 734 dog owners respectively in the United States and Japan, and some demographic differences were found, such as breed and neuter status. Data from completed questionnaires were subjected to factor analysis, and the resulting factors were tested for reliability. In the United States, factor analysis yielded 11 factors from 63 items that accounted for 52.9% of the common variance. In Japan, 15 factors were extracted, and these accounted for 57.0% of the common variance. The present factors for the United States were almost identical to the factors identified in a previous study, and similar factors were extracted in both countries. Therefore, the C-BARQ can function effectively as a fundamental behavioral evaluation system for dogs in Japan.