近年来，在外部监管机构的要求和企业自身发展的需求下，国内很多大型企业特别是大型国有企业在内部控制领域已开始了实践和探索，并取得了一定成果。然而大部分企业内部控制还十分薄弱，因内部控制缺失导致公司无法持续经营时有发生。A热力公司作为一家供热企业，经过几年的发展成为地区主要的供热企业之一，对地区经济的发展起着重要的作用。但从A热力公司目前的经营状况来看，经营亏损严重，资金短缺，靠借款维持日常运营，公司持续经营存在不确定性。公司要持续健康发展，需要扩大销售收入、提高利润、加速回款，这些都与销售与收款循环内部控制密切相关，因此深入分析A热力公司销售与收款循环内部控制现状，提出切实可行的改进方案势在必行。本文主要采用理论与实践相结合、归纳总结及穿行测试等方法对A热力公司销售与收款循环内部控制进行全面系统地研究。首先，回顾了内部控制发展的历程，阐述了内部控制基本理论。其次，在分析A热力公司销售与收款循环内部控制现状的基础上，依据内部控制理论深入剖析了A热力公司销售与收款循环内部控制存在的问题，从COSO内部控制理论出发提出了切实可行的改进方案，对A热力公司销售与收款循环内部控制进行了优化设计。最后，为了持续改进与完善A热力公司销售与收款循环内部控制，对该公司采纳改进方案后的内部控制执行情况进行了后续跟踪，通过设计评分方法和评价指标，对A热力公司销售与收款循环内部控制的有效性进行了评价，并对评价结果进行分析，提出了进一步改进之处。研究成果对于A热力公司建立健全销售与收款循环内部控制，提升经营管理水平，提高经济效益，具有现实的指导意义，对同行业的其他企业有一定的借鉴意义。同时也为我国热力行业建立内部控制框架和模型做出有益的尝试。

In recent years, under the external regulatory requirements and the enterprise's own development needs, many large domestic enterprises especially large state-owned enterprises put internal control into practice and exploration, and had get some achievements. However, the internal control of most enterprises is still weak, the fact that internal control flaw causes the company could not continue to operate appeared frequently. A heating company as a heating enterprises, after several years of development has become one of the main areas of heating enterprises, plays an important role in the development of the regional economy. But from the current operating situation, its business serious losses, lacks funds, on the group's borrowing to maintain the daily operation, uncertainty exists in continuous operation of the company. Company to the sustained and healthy development, need to expand sales, increase profits, accelerate on the back, and these are the sale and collection cycle of internal control are closely related, so the deep analysis of A heating company sales and collection cycle internal control present situation, proposed the feasible improvement scheme are imperative.This paper mainly adopts the combination of theory and practice, through onsite interviews and testing method for A heating company sales and collection cycle internal control comprehensively and systematically study. Firstly, reviews the history of the development of internal control, expounds the basic theory of internal control. Secondly, in the analysis of A heating company sales and current situation of internal control of receivables cycle basis, based on the internal control theory to analyze the A heating company sales and collection cycle internal control problems, starting from the theory of internal control of COSO proposed a feasible improvement schemes, the optimized design of the A heating company sales and receivable cycle of internal control. Finally, in order to improve the continuous improvement of A heating company sales and receivable cycle of internal control, the company adopted the implementation of internal control improvement scheme of follow-up, through design evaluation method and evaluation index of the specific evaluation on effectiveness of A heating company sales and receivable cycle internal control system, and analyzes the evaluation results, put forward the further improvement. Research results has a practical significance to establish and perfect the internal control for sales and collection cycle A heating company, enhance the management level, improve economic efficiency, has a certain reference significance to other enterprises in the same industry. At the same time also attempts to establish the internal control framework and model to make the beneficial for China's thermal industry.