BST-1 (bone marrow stromal cell antigen-1) is thought to be a key molecule involved in regulating the functional activity of cells in various tissues and organs. BST-1 can catalyze the hydrolysis of nicotinamide adenine dinucleotide (NAD+) to produce cyclic ADP ribose (cADPR), which activates the activity of intracellular Ca2+ signaling. Currently, the role of BST-1 regulation of Ca2+ signaling pathway in pathological myocardial hypertrophy is unclear. We found elevated expression of BST-1 in cardiac hypertrophy tissues of spontaneously hypertensive rats in our vivo study, subsequently; the mechanism of BST-1 action on myocardial hypertrophy was explored in vitro experiment. We used aldosterone (ALD) to induce H9C2 cellular hypertrophy. cADPR levels and intracellular Ca2+ concentrations declined and calcium-regulated neurophosphatase (CaN) activity and protein expression were decreased after BST-1 knockdown. And then activated T-cell nuclear factor (NFATc3) entry nucleus was inhibited. All of the above resulted in that H9C2 cells size was reduced by rhodamine-phalloidin staining. Thus, BST-1 may exacerbate cardiac hypertrophy by activating the Ca2+/CaN/NFATc3 pathway.