High Resolution Computed Tomegraphy(HRCT) was done in 22 cases of disseminated small nodular shadow from plainchest X-ray, which was included in metastic lesions, Miliary tuberculosis, pneumoconiosis etc. and followingresults were obtained. Mos of metastatic nodule (n=8) showed more than 1.5mm in diameter and the margin of nodulewas discrete(n=8) and many cases(n=8) were associated with thickened bronchovascular sheath or interlobular septumand hilar and mediastinal lymphnode enlargement(n=6). One case turned out to be not true nodule in HRCT butrevealed thickened interlobular septum and bronchovascular bundles. All cases of miliary tuberculosis(n=8) showedeven sized, well marginated and less than 3mm in diameter of nodule without evidence of thickening ofbronchovascular bundle or interlobular septum. Each cases of pneumoconiosis, histiocytosis X, diffusepanbronchiolitis(DPB) showed ill defined nodule and associate finding of DPB was peripheral bronchioloectasis.HRCT is useful method to exact evaluation of nodular lesion and find out associate findings for differentialdiagnosis of disseminated small nodular shadow in plain chest X-ray.