Study on effects of climate and forest types on soil organic carbon (SOC) in aggregation would attribute much to a better understanding of the variation pattern of soil aggregation organic carbon (OC), and provide researchers with data support for better predicting SOC response to global climate change. We sampled 0-20 cm surface soil layers from eight forests (including broad-leaved, mingled and coniferous forests) in three climate zones, subtropical, warm temperate and cool temperate zone. We also classified macro-aggregation and micro-aggregation with dry sieve method, measured their OC contents and percentages, and analyzed the relationship between aggregation OC and environmental variables. The results showed that both macro-aggregation and micro-aggregation OC contents were significantly affected by climate, and the OC contents of both macro-aggregation and micro-aggregation decreased with the increasing mean annual temperature (MAT). We suggested that this results were caused by the inhibited microbial decomposition activity by the low temperature in the higher latitude area. Aggregation OC percentage was significantly affected by forest types: higher in broad-leaved forests and lower in coniferous forests, resulting from different litter qualities and quantities between various forest types. In addition, soil pH and texture could also affect soil aggregation OC. The aforementioned results indicated that temperature rise and forest structure variation by human disturbance might cause soil aggregation OC content decrease, and lead exacerbate global climate change.