In patients with lung cancer, volatile organic compounds (VOCs) are excreted in exhaled breath. In this article, exhaled breath of 30 lung cancer paitients and 30 healthy people were collected, preconcentrated by solid-microextraction(SPME) and analyzed with gas chrom-atography and mass spectrometry (GC/MS). A predictive model composed of 5 VOCs out of 16 candidate VOCs detected in the lung cancer patients is constructed by discriminant analysis, with a sensitivity of 76.7% and specificity of 96.7%. We detected exhaled VOCs of 3 different lung cancer cell lines and human bronchial epithelial cell lines. 2-Tridicanone is considered the distinctive marker of lung cancer cells, which is found in lung cancer patients' exhaled breath as well. Compared to healthy people, patients with lung cancer had distinctive VOCs in their exhaled breath. The predictive model can work as diagnosis reference for lung cancer. VOCs found in lung cancer cell line help the cognition of the mechasim VOCs generating in lung cancer patients.