2005年以来，股权分置改革推动了中国境内的市场化进程，各项法律制度的颁布也标志着我国投资者合法权益越来越得到重视，公司外部治理环境的各项因素不断改善。短期融资券的发行提高了非上市公司参与资本市场活动的积极性，也在一定程度上提高了其财务信息透明程度。尽管如此，企业信息披露违规的案件仍时常发生，投资者的决策仍受到企业管理层对会计盈余信息操作的影响。本文试图结合公司治理的相关理论，首次综合上市公司与非上市公司财务数据，研究外部治理环境的市场化水平、政府干预和法制化进程三项指标对公司盈余管理的影响，以辨明我国目前的市场、政治、法律体制改革对于降低企业盈余管理水平，提高企业信息披露质量是否具有现实意义。研究基于上市公司与非上市公司在短期融资券市场披露的财务报告或经审计的财务报表数据，选取2005-2009年期间的100家公司作为样本，建立外部治理环境的市场化水平、政府干预和法制化进程等三项指标与盈余管理的模型。经数据统计分析及实证检验得出以下结论：对于全样本公司，外部治理环境的各项指标与公司盈余管理并不存在显著关系；上市公司的盈余管理水平显著受制于市场化、政府干预和法制化进程的影响。其中市场化水平越高，公司盈余管理水平则越低，但政府干预和法制化进程对盈余管理存在正向影响；非上市公司在模型的适用性方面存在问题导致回归结果都不显著。此外，控制外部治理环境各项指标和其他变量后，上市公司由于受到市场、投资者、法律等强有力的监管压力，其盈余管理的水平较非上市公司较低，但无法判断外部治理环境对不同公司的影响是否存在差异效应。基于上述研究结论，本文从深化市场体制改革、转变政企关系、完善法律监管等层面提出了适当的政策建议。

Since 2005, the share-trading reform has promoted the process of marketization in China. The promulgation of laws and regulations also marks the legitimate rights and interests of investors get more attention. The external governance environment continues to improve. Issuance of short-term financing bills stimulated unlisted companies involved in capital market activities, to some extent enhancing transparency of financial information. Nevertheless, cases for information disclosure violations still frequently happen, and investors' decisions are still subject to the operation of accounting earnings information from the corporate management. Based on theories of corporate governance, this paper firstly combines financial data of listing companies and unlisted companies, and analyzes the effect of three indicators of external governance environment (market-oriented level, government intervention, legal process) to earnings management, for identifying whether our current market, political, legal reform has practically reduced the level of earnings management and improved companies’ information disclosure quality.According to financial reports or audited financial statements disclosed by the listed companies and unlisted companies in the short-term financing bills market. This paper has selected 100 companies for the period 2005-2009 as the sample to establish empirical model of external governance environment (market-oriented level, government intervention, the legal process and earnings management. Statistical analysis and empirical test have got the following conclusions: For the full sample company, the external governance environment indicators were not significantly related with corporate earnings management; earnings management of listed companies was significantly constrained by market-oriented level, government intervention and legal system. The higher the level of the market was, the lower the extent of earnings management would be. But government intervention and legal process had positive impact on earnings management; for unlisted companies, in terms of applicability of the model regression results were not significant. In addition, controlling three indicators of external governance environment and other variables, earnings management of listed companies was lower than non-listed companies, due to strong regulatory pressure from market, investors, laws and other regulations. However, it can not be confirmed whether external governance environment differentially affected different companies. Based on the above findings, this paper put forward appropriate policy recommendations to deepen the market reform, change government functions and improve legal regulation.