This paper profoundly analyses balance of payments of china with relative data in 1985 - 2006 period and found that : saving exceeding investment continuously in the long run is the fundamental cause of twin - surplus of china which reflects the inner imbalance of economic structure of china under background of intensive international specialization and industry upgrading and transfer 摘要本文通过对1985 - 2006年中国国际收支及相关数据的深入分析，发现中国长期存在的储蓄持续大于投资是中国国际收支长期保持双顺差而失衡的根本原因。
