Moso bamboo forests in Zhejiang Province, China, are important for capturing carbon from the atmosphere. A study from 2004 to 2014 found that the culm density and size of the bamboo increased over time. Despite this, the structure of the forests could be improved for better bamboo growth. The forests acted as a carbon sink, with an average increase of 0.94 Mg C ha−1 yr−1. Younger bamboo plants contributed more to carbon storage than older ones. The carbon stock rose with higher culm density, size, and age. Optimizing forest structure and management could increase the carbon sequestration potential of these bamboo forests.