Moso bamboo (Phyllostachys pubescens) has high carbon sequestration potential and plays an important role in terrestrial carbon cycling. Quantifying the temporal change in Moso bamboo forest carbon stocks is important for understanding forest dynamics and global climate change feedback capacity. In 2009, 168 Moso bamboo forest sample plots were established in Zhejiang Province using National Forest Continuous Inventory protocols and enhanced measurements. These plots were revisited and remeasured in 2014. By comparing the two years, culms number in age classes 2 and 4 increased by 12.3% and 82.5%, respectively, while that in age classes 1 and 3 decreased by 14.7% and 0.03%, respectively. The total aboveground culms carbon stocks increased by 2.95 Mg C ha⁻¹ in the sample plots. On average, age classes 2 and 4 contributed 25.5% and 86.7% of the change in total carbon stocks, respectively. The carbon sequestrated by aboveground culms was 0.42 Tg C year⁻¹, accounting for 1.55 Tg CO₂ year⁻¹ in Moso bamboo over an area of 0.78 million hectares in Zhejiang Province. The change in Moso bamboo carbon stocks did not correlate with environmental factors, but significantly increased with increasing culms number and average diameter at breast height (DBH). Our study helps contribute to improvements in Moso bamboo forest management strategies and promote carbon sequestration capacity.