上市公司年度报告作为投资者获取信息的主要途径，其可读性对于降低信息不对称、提高市场公平和效率具有重要意义。然而，研究表明，随着时间推移，年度报告的可读性呈下降趋势，可读性较差的报告可能是公司试图掩盖不利消息的表现，因此可能带来信息不对称问题。本文旨在探讨年度报告的可读性与信息不对称之间的关系，以中国上市公司的年度报告为研究对象，构建了基于文本特征的可读性指标，并通过股票买卖价差来衡量信息不对称程度。研究发现，年度报告的可读性与信息不对称之间存在复杂的关系。具体而言，上市公司在披露年度报告时存在“信息模糊”和“信息供给”两种动机。当公司存在“信息模糊”行为时，报告的可读性下降，信息不对称增加；而当公司意图“信息供给”时，尽管可读性同样下降，但由于信息供给更详尽、更专业，信息不对称程度反而减轻。本文利用不同的文本特征在度量可读性上的不同侧重点区分了这两种动机，稳健性检验的结果证明以上结果是稳健的。本文的研究结果对于投资者评估公司、提高市场效率、降低交易成本具有重要意义。

As the primary source of information for investors, the readability of annual reports plays a crucial role in reducing information asymmetry and enhancing market fairness and efficiency. However, studies have shown that the readability of annual reports tends to decline over time, and reports with poor readability may be indicative of companies attempting to conceal unfavorable information, potentially leading to information asymmetry issues. This paper aims to explore the relationship between the readability of annual reports and information asymmetry, focusing on Chinese listed companies' annual reports. We construct readability indicators based on text features and measure information asymmetry using stock trading spreads. Specifically, companies exhibit two motives— "information fuzziness" and "information provision"—when disclosing annual reports. When employing "information fuzziness" tactics, the readability of the report decreases, leading to an increase in information asymmetry. Conversely, when intending to "provide information," although readability similarly decreases, the more detailed and professional information provision results in a reduction of information asymmetry. This study distinguishes between these two motives based on different textual features emphasizing readability, and robustness tests confirm the validity of the results. The findings have significant implications for investors in evaluating companies, enhancing market efficiency, and reducing transaction costs.