Abstract: Objective:To evaluate the value of high resolution CT(HRCT) in diagnosing solitary pulmonary nodule(SPN). Methods:Sixty-two cases with SPN including 31 cases of peripheral lung cancer,29 cases of benign SPN and 2 cases of metastatic tumors were investigated. The border patterns and internal characters of different process nodus were analyzed. Results:The minute structures of SPN could be thoroughly displayed by HRCT. Lobulation signs in 37 cases, sentus signs in 30 cases, pleural indentation in 50 cases, calcification signs in 17 cases, blood vessel cluster in 20 cases and bronchus signs in 15 cases were observed. Conclusions:HRCT can clearly display the internal structures of SPN, which is an effective way to discriminate the benign and malignant SPN. The observation of volume rendering combined with multi-planar reconstruction image of MDCT can clearly display the characteristic lesion features.