CT was carrid out in 33 nodules showing non-calcified nodular shadow on the chest radiographs or conventional tomograms, and measurement of CT number and preparation of the distribution chart were performed. Five nodules and 3 nodules out of 14 benign lesions were diagnosed as a benignity by CT number and distribution chart of CT number, respectivery. CT could supply information which are necessiated for the qualitative diagnosis of the pulmonary nodules.