In this study, the regulatory effects of mitochondrial Ca2+ on phosphodiesterase 2 (PDE2)/cAMP/PKA axis and the phosphorylation of mitochondrial transcription factor A (TFAM) as well as the growth of CRC cells were systematically investigated both in vitro and in vivo. Our findings demonstrated that MCU-induced mitochondrial Ca2+ uptake activated mitochondrial PDE2 in CRC cells. This evidence concerns the gene PDE12 and colorectal carcinoma.