摘 要:本文通过国内外对会计估计变更的研究，以及会计在中国市场经济中重要地位。阐述了会计估计变更和会计信息质量的相关概念，并通过四川长虹的MBO案例分析会计估计变更对会计信息质量的影响。其中，认真分析应收账款坏账的计提和存货跌跌价准备的计提对四川长虹净利润的影响。阐明了不同的会计估计对企业净利润的影响，及会计估计变更对会计信息质量的重大影响。以此，提醒投资者应该辩证的看待上市公司提供的会计报表，认真解读上市公司的财务状况和经营成果。只有真实、可靠、完整的财务报表才能全面、准确的反映企业的财务状况和经营成果。并对投资者如何加强自身修养、政府如何完善会计监督体系、如何改善资本市场的投资环境，为保障投资者的相关利益提供建议。

关键字：会计估计变更；应收账款；存货；会计信息质量

ABSTRACT:This thesis aims to explain the concepts of changes in accounting estimate and the quality of accounting information by studying changes in accounting estimate both at home and abroad and the important role that accounting plays in China’s market-oriented economy. It specifically deals with the MBO case of Sichuan Changhong Electric Co. Ltd, trying to analyze the different that changes in accounting estimate will make in the quality of accounting information. We will painstakingly analyze the influence of counting and drawing of bad accounts receivables and inventory falling price reserves on the net profit of Sichuan Changhong. The influence of different accounting estimates on the net profit of an enterprise and the great influence of changes in accounting estimates on the quality of accounting information will be clearly explained. Consequently, we will warn small and medium investors that accounting statements provided by listed companies should be treated dialectically. They should scrutinize the financial situation and records of performance of listed companies. Only authentic, reliable and complete financial statements can reflect the financial situation and records of performance of the companies comprehensively and accurately. Finally,  suggestions will be given on how small and medium investors can strengthen their self-cultivation and how governments can improve the accounting supervision system, better the investment environment of the capital markets in order to protect the interests of small and medium investors.

Key words: Change in accounting estimate; Accounts receivables;Stock; Quality of accounting information