Objective：The aim of this study is to evaluate the impact of putrescine on oocyte quality in aged mice during in vitro maturation（IVM）. Additionally，the effect of putrescine on mitochondria-associated endoplasmic reticulum membrane（MAM）in aged mouse oocytes will be investigated. Methods：Germinal vesical（GV）stage mouse oocytes were cultured in vitro until they reached the Meiosis（M）Ⅱ stage. The young control group consisted of 8-week-old mice，while the old control group consisted of 40-week-old mice. The old experimental group consisted of 40-week-old mouse oocytes supplemented with 0.5 mmol/L putrescine in the IVM solution. The oocyte quality was assessed by detecting the first polar body（PB1）extrusion rate，2-cell rate，blastocyst formation rate，cortical granule distribution，spindle abnormality rate，and chromosome abnormality rate of oocytes at stage MⅡ. Additionally，MAM in MⅡ- stage oocyte was observed using transmission electron microscopy，the content of key molecules for Ca²⁺ transfer was detected by qPCR，and the Ca²⁺ levels in mitochondria，endoplasmic reticulum，and cytoplasm were determined using Ca²⁺ probes. Mitochondrial function was assessed by measuring mitochondrial membrane potential，ATP content，and reactive oxygen species（ROS）levels. Results：Putrescine increased the rate of PB1 extrusion（P < 0.05）and the blastocyst rate（P < 0.05）in oocytes of aged mice and significantly reduced the rate of cortical granule distribution abnormalities（P < 0.01），spindle abnormalities（P < 0.01），and chromosomal abnormalities（P < 0.05）. The oocytes contained MAM structures. Putrescine prevented the shortening of MAM spacing（P < 0.001）in oocytes of aged mice and reduced the levels of key molecules for Ca²⁺ transfer between MAM（P < 0.05）. Meanwhile，putrescine improved mitochondrial function（P < 0.05）and reduced intracellular ROS levels（P < 0.001）by alleviating mitochondrial calcium overload（P < 0.001）caused by rapid Ca²⁺ transfer between MAMs. Conclusion：The addition of putrescine to in vitro maturation cultures significantly improved the quality of oocytes of aged mice. Putrescine also alleviated mitochondrial calcium overload and improved mitochondrial function by modulating inter-MAM Ca²⁺ transfer.