Anthocyanins are a type of flavonoids that are natural water soluble glycosidic pigments with efficacious anti-cancer effects, which have good biological activity against many cancers including colorectal cancer (CRC). However, the exact molecular mechanism used by anthocyanins against cancer is unclear; it is also unclear what a reasonable dosage might be for their use against colorectal cancer. Western blotting, immunohistochemistry, MTT assay, xenograft model, and hematoxylin-eosin (HE) staining were used to perform the experiments. Compared with the control group, anthocyanins could significantly inhibit the cell viability and proliferation and promote the apoptosis of human colon cancer HT29 cells. Furthermore, anthocyanins reduced tumor weight and volume in a colon tumor mouse model and downregulated the expression of PI3K protein, inhibited AKT expression and phosphorylation, decreased the Bcl-2 and Bax ratio and reduced survivin protein expression in the tumor tissue. Anthocyanins promoted apoptosis of CRC cells and inhibited colon cancer growth of xenografted tumors. Mechanistically, anthocyanins enhanced the Bcl-2/Bax and caspase-dependent apoptotic pathways through targeting the PI3K/AKT/survivin pathway, resulting in impairment of growth of CRC.