中国南方石笋氧同位素（δ¹⁸O_c）是重建轨道和千年尺度季风气候变化的重要指标，但其与区域降水量的关系仍存在
不确定性，这不仅影响了对δ¹⁸O_c气候指示意义的准确解读，也制约了基于该指标探讨季风气候驱动机制的研究。文章整合了已发表的21~11 ka B.P.时段中国南方石笋δ¹⁸O_c数据和HadCM3B模式模拟结果，分析了冰期—间冰期转型阶段石笋δ¹⁸O_c与区域降水的关系。研究发现：在轨道尺度上，末次冰消期中国南方石笋δ¹⁸O_c的变化能反映区域夏季降水量的长期演变；而在千年尺度上，则主要表征区域年降水量的波动特征。具体而言，在冰期向间冰期过渡的过程中，石笋δ¹⁸O_c呈现持续偏负趋势，对应区域夏季降水量的逐步增加；而在YD和HS-1事件期间，石笋δ¹⁸O_c显著偏正时，年降水量反而增多。值得注意的是，仅考虑降雨量变化获得的降水δ¹⁸O_p序列与中国南方石笋δ¹⁸O_c序列均进行距平处理后的对比表明：虽然石笋δ¹⁸O_c与不同时间尺度的区域降水指标存在前述关联，但不宜将其气候意义直接等同于区域夏季降水量或年降水量。

The stalagmite δ¹⁸O_c records from southern China serve as a crucial paleoclimate archive for reconstructing orbitaland millennial-scale variations of the Asian monsoon system. Nevertheless, the precise linkage between these δ¹⁸O_c signals and regional precipitation remains debated, posing challenges for both the climatic interpretation of δ¹⁸O_c variations and investigations of driving mechanisms of monsoon variations. This study synthesizes published stalagmite δ¹⁸O_c records (21-11 ka B.P.) from southern China with HadCM3B model simulations to examine the δ¹⁸O_c -precipitation relationship during the last deglaciation. Our analysis reveals distinct scale-dependent relationships: on orbital timescales, the δ¹⁸O_c variations reliably track long-term changes in summer precipitation, while millennial-scale δ¹⁸O_c fluctuations primarily reflect variations in annual precipitation. The transition from glacial to interglacial conditions is marked by progressively depleted δ¹⁸O_c values, corresponding to increasing summer rainfall. In contrast, during abrupt climate events such as YD and HS-1, enriched δ¹⁸O_c values coincide with enhanced annual precipitation. Through comparative analysis of δ¹⁸O_p anomalies with the precipitation-weight and stalagmite δ¹⁸O_c anomalies, we demonstrate that while the aforementioned relationships exist across different timescales, stalagmite δ¹⁸O_c cannot be unambiguously interpreted as a direct proxy for either summer or annual precipitation amounts.