次贷危机已经成为全球性的经济危机，给许多国家的宏观经济带来了巨大的冲击。人们在反思这次危机时，很自然地会想到巴塞尔协议，这一关于资本监管的全球性的新的资本协议框架。本文结合本次经济危机，剖析新巴塞尔协议关于资本充足率的规定的顺周期性，包括其表现、影响途径及其修正的讨论。新巴塞尔协议关于资本充足率的要求通过还贷能力、信用等级、资本缓冲、不良贷款拨备以及影响货币政策效力等途径影响经济周期。通过相关的实证研究和讨论，我们从信用评级方法、监管及宏观政策角度探索了缓解这一问题的方法。

The sub-prime crisis has become a global economic crisis, having brought tremendous macroeconomic shocks to many countries. When people think about this crisis, it is natural to think of the Basel agreement on capital regulation, a global framework of the new Capital Accord. In this paper, we analysis the procyclicality of the capital adequacy ratio in Basel II, including its performance, the pathways and the discussions about amendment. The capital adequacy requirements in Basel II influence the economic cycle through the pathway of repayment capacity, credit rating, capital buffer, provision for non-performing assets and impacting the effectiveness of monetary policy. Through the relevant empirical studies and discussions, we explore the methods to mitigate the effect from the perspectives of credit rating methods, supervision and macroeconomic policies.