Qianjinweijing Tang (QJWJ) is a classic traditional Chinese formula that is often used in the treatment of treat lung cancer (LC). However, the underlying cellular mechanisms of the anticancer effects of QJWJ remain unclear. Cell viability was determined by MTS assay and levels of apoptosis measured by flow cytometry. Animal experiments were conducted to determine the effects of QJWJ on tumour growth in vivo. We used a proteomics approach to study the effects of QJWJ on LC cells and applied bioinformatics analysis to identify differentially expressed proteins that were validated by Western blotting. QJWJ inhibited the proliferation of LC cells and induced apoptosis. The tumour growth delay effects of QJWJ were confirmed in vivo. We identified 104 differentially expressed proteins following QJWJ treatments of which 45 proteins were upregulated and 59 proteins were downregulated. The levels of differentially expressed proteins were validated by Western blotting. Our study indicated that QJWJ has anticancer effects in vivo and in vitro and that these effects are mediated by modulating the expression of tumour-related proteins. This article is protected by copyright. All rights reserved.