中文摘要：

不同制度环境下外部审计质量对商业信用模式的选择存在一定的影响。研究结果表明，高质量审计可以使交易双方采用融资成本较低的商业信用模式。由于预算软约束的存在，在国有企业中，无论制度环境的好坏，高质量外部审计对商业信用模式的影响不显著；民营企业的审计质量倾向于选择融资成本较低的商业信用模式，并且在制度环境较差的地区，这种影响更加显著。因此，外部审计质量对预算软约束、政府干预与法制环境有替代作用。

英文摘要：

External audit quality has a certain effect on the choice of commercial credit mode in the context of different insti- tutional environments. Research shows that high-quality auditing can make trading parties adopt a commercial credit mode with relatively low financing cost. Due to the soft budget constraint, high-quality auditing has no significant effect on commercial credit mode in the state-owned enterprises no matter whether the institutional environment is good or bad. However, private enterprises prefer to choose a commercial credit mode with relatively low financing cost, in which such effect is more significant, especially in relatively unsatisfactory institutional environment. Therefore, external audit quality has a substitution effect on soft budget con- straint, government intervention and legal environment.