C‐natriuretic peptide (CNP) is the central regulator of oocyte meiosis progression, thus coordinating synchronization of oocyte nuclear‐cytoplasmic maturation. However, whether CNP can independently regulate cytoplasmic maturation has been long overlooked. Mitochondrial DNA (mtDNA) accumulation is the hallmark event of cytoplasmic maturation, but the mechanism underlying oocyte mtDNA replication remains largely elusive. Herein, we report that CNP can directly stimulate oocyte mtDNA replication at GV stage, and deficiency of follicular CNP may contribute largely to lower mtDNA copy number in in vitro matured oocytes. The mechanistic study showed that cAMP‐PKA‐CREB1 signaling cascade underlies the regulatory role of CNP in stimulating mtDNA replication and upregulating related genes. Of interest, we also report that CNP‐NPR2 signaling is inhibited in aging follicles, and this inhibition is implicated in lower mtDNA copy number in oocytes from aging females. Together, our study provides the first direct functional link between follicular CNP and oocyte mtDNA replication, and identifies its involvement in aging‐associated mtDNA loss in oocytes. These findings, not only update the current knowledge of the functions of CNP in coordinating oocyte maturation but also present a promising strategy for improving in vitro fertilization outcomes of aging females.C‐natriuretic peptide (CNP) is a critical regulator of the progression of oocyte nuclear maturation by maintaining meiotic arrest. However, whether CNP can independently regulate cytoplasmic maturation has been long overlooked. Our study provided the evidence that CNP essentially stimulates the accumulation of mitochondrial DNA (mtDNA), the hallmark event of oocyte cytoplasmic maturation, in oocytes, via cAMP‐PKA‐CREB1 signaling cascade. Moreover, we also identified the involvement of inhibited follicular CNP‐NPR2 signaling in age‐related mtDNA loss in oocytes. [ABSTRACT FROM AUTHOR]