[目的/意义]对网络交易中的逆向选择问题进行系统分析，为缓解网络交易中的信息不对称问题提供理论依据，以期提升网络交易市场效率，推动电子商务产业健康持续发展。[方法/过程]在界定网络交易中逆向选择概念的基础上，分析逆向选择的主要表现，运用文献研究和专家调查法探讨逆向选择的形成原因，并提出相应的规避措施。[结果/结论]网络交易中逆向选择与道德风险问题划分标志被明确；网络交易中逆向选择问题主要表现在所购商品物非所值、商品配送时效降低及商品破损风险增加；逆向选择形成原因包括商品文本型描述信息缺失和虚假、商品图片型描述信息失真、消费者评论信息不真实不全面、电子商务平台评价数据不可靠、经验商品性能无法通过信息分辨、商家配货信息虚假和缺失、客服传递过程中的信息偏差、物流服务信息不具体、物流流转信息不准确，影响力依次递减。

[Purpose/Significance] A systematic analysis of adverse selection in online transactions is conducted to provide a theoretical basis for mitigating information asymmetry in online transactions, with a view to enhancing the efficiency of the online transaction market and promoting the healthy and sustainable growth of the e-commerce industry. [Method/Process] On the basis of defining the concept of adverse selection in online transactions, the article discussed the main performances, used literature research and expert survey methods to explore the causes of adverse selection, and proposed corresponding evasion solutions. [Result/Conclusion] The division between adverse selection and moral hazard problems in online transactions is clarified. The adverse selection in online transactions is mostly represented in the non-value of acquired products, a decrease in commodity distribution timeliness, and an increase in the danger of commodity damage. The formation reasons of adverse selection include missing and false information on text-based descriptions of goods, distorted information on picture-based descriptions of goods, untrue and incomplete information on consumer reviews, unreliable evaluation data on e-commerce platforms, empirical goods performance cannot be discerned through information, false and missing information on merchants' dispensing, information bias in the process of customer service delivery, unspecific information on logistics services, and inaccurate information on logistics flow, with all the factors' influence decreases in order.