中文摘要：

安然事件以来，审计任期与盈余（经审计的）质量的关系成为了研究热点。本文运用中国证券市场1998—2004年上市公司的公开数据，同时从事务所任期与合伙人任期两大层面实证检验了审计任期与盈余质量之间的关系。实证结果显示：随着会计师事务所审计任期的增加，盈余质量显著地表现出先逐渐上升后逐渐下降的倒U型趋势，且拐点稳定在6—8年之间；而随着签字注册会计师审计任期的增加，盈余质量虽然总体逐渐上升，但此趋势尚不足够显著。

英文摘要：

The relationship between audit tenure and earnings （or audit） quality has gained increasing interest globally, especially since the issuance of the Sarbanes-Oxley Act （2002） in the United States of America. Rotations of audit firms or audit partners are the main policy initiatives that have been considered on many security markets around the world to deal with public concerns about audited earnings quality. Theoretically, the tenure of incumbent auditor （on the audit firm level and audit partner level） may have double effects on earnings quality of clients＇ annual financial reports. This empirical paper compares the effects of audit firm tenure and audit partner tenure on audited earnings quality, and considers the roles of some peculiar regulatory and cultural factors in China. Using public available data during 1998-2004 about listed companies on China security market, the relationship between audit tenure and earnings quality is analyzed under the Chinese context. Specifically, both the audit firm tenure and the audit partner tenure are included regarding audit tenure; and the magnitude of discretionary accounting accruals is used as proxy for earnings quality. Our empirical results show that： （1） the earnings quality of China listed companies manifests a significant inverse U-shaped tendency during the audit firm tenure, with an inflection point varying between 6-8th year of the tenure; （2） Although the earnings quality also manifests an increasing tendency during the whole audit partner tenure, the relationship is not statistically significant enough. The results are considered attributable to some peculiar regulatory and cultural factors in China.