Objective In recent years,the detection rate of pulmonary nodules is getting higher and higher.Nodules measuring >8mm show a significantly increased risk of malignancy,but the clinical and imaging characteristics of>8mm in asymptomatic solitary pulmonary nodules(SPNs)have not been reported detailed.Methods We retrospectively analyzed the clinical,imaging and pathological data with SPNs diagnosed by CT guided percutaneous lung biopsy in our hospital.They were classified into two groups,asymptomatic or symptomatic.The differences of above features between them were analyzed.Results From Jan of 2011 to April of 2015,697 patients with SPNs were retrospectively reviewed.326 were asymptomatic.Age,pack-years and size of nodules were significantly lower in asymptomatic group(55.49±11.95 y,34.21±22.64pack-years,18.32±4..4mm)than in symptomatic group(57.42±11.09 y,42.66±41.39 packyears,19.14±4.94 mm,P<0.05).In the asymptomatic group,the history of cancer,metastatic cancer,benign tumor in the benign lesions and IIIa or earlier stage of lung cancer were significantly more than in the symptomatic group(P<0.05).There was no significant difference in the edge,density and location of SPNs between the two groups.Conclusion The cancer risk of>8mm asymptomatic SPNs is not lower than symptomatic patients.The younger,smaller nodules,less pack-years and earlier stage of lung cancer were discovered in asymptomatic patients than in symptomatic patients with >8mm SPNs.It is necessary to pay attention to the>8mm asymptomatic SPNs in clinic.It is helpful to improve the prognosis of lung cancer.