Abstract: We discussed the value of liquid cytology system in the sputum of patients with lung cancer. METHODS：Samples which were treated with conventional preparation and those that were treated with LCT in 2009 were collected. All of the sputum specimens were diagnosed by the same cytologic pathologists. RESULTS：A total of 13 244 sputum specimens were evaluated with conventional preparation，454 (3.428%) of which were positive. 170 were squamous cell carcinoma，the positive rate was 1.284%，130 were adenocarcinoma，the positive rate was 0.982%. Also 210 samples were positive among 3 227 sputums specimens treated with LCT，the positive rate was 6.508%，63 were squamous cell carcinoma，the positive rate was 2.824%，89 were adenocarcinoma，the positive rate was 3.989%. The overall positive rate of the sputum specimeus delivered by oncology department was 11.022%. CONCLUSION：LCT smear contributed to increasing the positive rate of sputum cytology and it will be helpful in the screening and early diagnosis of high-risk populations with lung cancer.

Key words: lung cancer, cytology, sputum, liquid –based cytologic test