Abstract： Objective To explore the clinical application of CT-guided percutaneous lung biopsy(PTLB)combined with fluorescence cytology rapid on-site evaluation(F-rose)in the cytological diagnosis of lung malignant tumors.Methods One hun-dred and twenty hospitalized patients who underwent minimally invasive CT-guided percutaneous lung puncture biopsy in our hospital were collected.Under CT-guided localization of the lesion area fine-needle puncture sampling,the puncture needle resid-ual fluid was applied to two slides,and respectively,the other two clean slides were stacked,lightly pressed,and pulled apart at a uniform speed in the reverse direction to make four smears,which were quickly placed in 95％alcohol for fixation and then removed for drying.Differences between the two staining methods in lung occupying lesions were evaluated by fluorescent ROSE staining and ROSE staining.Ninety-four patients were screened for definitive pathological diagnosis based on histopathological findings,of which 66 were confirmed malignant tumors and 28 were non-neoplastic lesions.Patients with fungal and Mycobacte-rium antacidum-positive is non-neoplastic lesions.The sensitivity and specificity of the two methods for the cytological diagnosis of lung malignant tumors were analyzed using the pathohistological results as the gold standard,and the differences in the cyto-logical diagnostic value of the two methods for lung malignant tumors were evaluated.Results The overall confirmed diagnosis rates of fluorescent ROSE and ROSE groups were 60.64％and 48.94％respectively(P＜0.05);the sensitivity of diagnosing lung malignant tumors was 68.18％in both groups(P＞0.05);and the specificity of the fluorescent ROSE and ROSE groups were 42.86％and 3.57％(P＜0.05),respectively.Conclusion Fluorescence ROSE combined with PTLB can improve the con-firmation rate of lung occupying lesions,especially the specificity of cytological diagnosis of lung malignant tumors,which has certain clinical application value in the cytological diagnosis of lung occupying lesions.