In 2008, CLAs received a no-objection letter from the FDA on its generally recognized as safe (GRAS) status for certain foods. However, aside from the mixture of c9, t11-CLA and t10, c12-CLA, other CLA mixtures are still not used in food production. The effects of different concentrations (25, 50, 100, and 200 mmol/L) of CLA mixture (c9, t11-CLA and t9, t11-CLA) on the human colorectal carcinoma cell line Caco-2 cells after various treatment times (1, 2, 3, and 4 days) and the induced apoptosis were examined in the study. The mRNA expression level and activities of caspase-3, -8, and -9 were determined via quantitative real-time PCR and caspase-3, -8, and -9 assay kits. The results indicated that the CLA mixture inhibited the proliferation of the Caco-2 cells, and the antiproliferative effects were closely related to treatment time and concentration. Meanwhile, the CLA mixture increased the mRNA expression level and activities of caspase-3, -8, and -9 compared with control which suggested apoptosis induced by CLA mixture was related to the caspase pathway. In conclusion, the CLA mixture can inhibit Caco-2 cell proliferation and induce its apoptosis through increasing caspase 3, 8, and 9 expression and activities.Practical applications: In the food industry, lactic acid bacteria (LAB) are generally recognized as safe and important for the production of fermented food and may be used as probiotic bacteria in the human gastrointestinal tract, contributing to pathogen inhibition and immunomodulation. C9, t11-CLA and t9, t11-CLA isomers used for the present study were obtained from the conversion of linoleic acid by Lactobacillus helveticus L7 (used as a probiotic bacterial in our laboratory). Here, the mixture of c9, t11-CLA and t9, t11-CLA had a synergistic antiproliferation effect on the Caco-2 cells which suggested that the CLA mixture has potential health value, and can be a beneficial supplement in the food industry.