Abstract: Objective To investigate the potential antiproliferative and proapoptotic effects of crocin on human lung adenocarcinoma cell line SPCA1 and explore its possible anticancer mechanism. Methods Different doses of crocin （1，2，4，8，16mg／ml） were added to the SPC-A1 cells. The MTT assay was performed to reveal the inhibitory effect on cell proliferation. Inverted microscope was used to observe the morphological changes of the SPCA1 cells. Flow cytometry using annexin V-FITC／PI staining was employed to measure the cell apoptosis and cell cycle.RTPCR was used to detect mRNA expressions of p53， Bax and Bcl-2. Results Crocin treatment inhibited the proliferation and induced the apoptosis of SPC-A1 cells in a dosedependent manner. After being treated by crocin for 48h，evident morphological changes including membrane shrinking，rounding shapping and budding to form apoptotic characters were observed. Flow cytometry showed the proportion of SPC-A1 cells increased at G₀／G₁ phase while it decreased at S and G₂／M phases，indicating SPC-A1 cells were arrested at G₀／G₁ phase by crocin treatment at 48h. The expressions of p53 and Bax mRNA were upregulated，and the expression of Bcl2 mRNA were downregulated in a dose-dependent manner. Conclusion Crocin can inhibit the proliferation of lung adenocarcinoma cell line SPCA1 through inducing cell cycle arrest and apoptosis， with the possible mechanism of dysregulation of p53， Bcl-2 and Bax expression.