Decreased oocyte developmental potential is an important factor affecting fertility and embryonic development. Increasingly evidence is suggested that the decline in oocyte quality caused by aging after in vitro ovulation is a limiting factor affecting the development of assisted reproductive technologies in humans. However, the key molecular mechanisms underlying the decline in the quality of post-ovulatory aging (postOA) oocytes have not been fully characterized. Here, we obtained the protein profile and transcript profile of in vitro postOA oocytes. Particularly, we found the differential protein enrichment feature, such as RNA decay and chromosome segregation pathway. Moreover, transcriptomics analysis shows that down-regulated transcripts are increased in postOA oocytes in humans and mice. The mRNA-decapping enzyme 1A (DCP1A) as a key factor, influences the abundance of oocyte specific expressed marker protein Y-box-binding protein (YBX2), which leads to instability of maternal mRNA and more prone to de