“信号”是信号传递理论的核心，在本文中被定义为“传递发送方真实意愿信息的表述、行为或特质，以试图改变其他个体的旧有信念和意向”。信号传递理论源于对个体心理与行为的分析——个体信息在博弈双方之间分布的不对称使得一方出于获益、止损或规避风险的心理而无法产生对方所预期的行为，而信号的传递则能够在一些时候解决由信息分布不均衡而引发的行为困境。但其影响并不总是奏效。并且，通过文献梳理发现，现有信号传递研究在层次、状态情境、有效性等方面存在局限，影响其对于信号传递理论的应用性与信号传递的有效性的论证。基于此，本文选择中国环境监管案例，试图对现有文献的不足进行补充，并回答“中央政府环境监管信号的传递是否能够改变地方政府的环境监管行为；更进一步地，如果可以，哪些信号能够更有效地改变地方政府的环境监管行为，如果不行，那么原因又是什么”。本文将符合信号传递定义的中央政府环境监管信号全部纳入分析，通过定量研究，探讨了其对于直接接收者（省级政府）监管行为的影响，并进一步检验了哪些信号（信号的哪些性质）的影响更加有效，随后通过中央信号与省级政府调节行为交互项的引入，论证了信号传递链中重要的“中间环节”对信号传递效果（市级政府监管行为）的影响。最后，基于“京津冀大气污染协同治理”案例，质性分析了中央政府信号对接收者（省级政府）行为的影响过程和机制。本文的主要研究发现如下：（1）在非自由竞争状态下，信号的传递依然能够对信号接收者的行为产生影响、破解个体行为困境。（2）不同的信号/信号的不同性质对信号接收者行为影响的有效性不同。在中国环境监管案例中，文件的颁布，以及文件的可信性、强烈性、（监管目标）清晰性对接收者行为的影响更佳。（3）在有着多个环节的信号传递链中，信号的最终传递效果会受到重要的“中间环节”的显著影响。（4）不同信号的配合使用在一些时候（区域治理中）对接收者行为影响更有效。本文不仅对信号传递理论作出了补充，在实践中，也为更好地调动信号接收者的行为，尤其是破解中国地方政府环境监管行为困境、缩小环境政治领域重点关注的中国地方政府环境政策执行偏差问题提供了解决思路。

‘Signal’ is the core of signaling theory. In the present research, signal was defined as ‘expressions, activities or attributes of signal senders, to alter the beliefs or intentions of others (receivers) ’. Signaling theory originates from the analysis of psychology and behavior. The asymmetry of individual information distribution between two sides makes one side could not produce the expected behavior of the other side due to the psychology of profit, stop loss or risk aversion. While signaling, at some times, may solve the behavior dilemma caused by the imbalance of information distribution. However, its impact does not always work. Moreover, through the review of literature, we found that existing research about signaling theory has other limitations, for example, in research levels, state, context, effectiveness, etc., which may restricts its demonstration of the applicability of signaling theory and the effectiveness of signaling. In this way, the present research selects the environmental regulation in China as the critical case, to supplement the insufficiency of the existing literature, and answer the research question “whether central government’s environmental regulation signal can change the local government’s environmental regulation behavior; if so, which signals can change the local government’s environmental regulation behavior more effectively, and if not, what are the reasons?” In the research, all the environmental regulation related behaviors of central government that meet the definition of signal are included in the analysis. Through the quantitative method, the signals’ impact on the environmental regulation behavior of the receivers (provincial governments) is discussed, and further tests of which signals are more effective. Then, the interaction terms of central signal and provincial government regulation behavior are introduced to demonstrate the significant influence of moderators in the signal transmission chain on the signaling effect. Finally, by analyzing the case of collaborative governance of Beijing-Tianjin-Hebei on air pollution, the research explores the influence process and mechanism of the central government environmental regulation signals and their receivers’ (provincial governments) behaviors from the qualitative perspective. The main findings of this paper are as follows:(1) In general, signals can still affect the receivers’ behaviors and solve the behavior dilemma in the state of non-free competition.(2) The effect of different signals/signal properties on the receivers’ behaviors is different. In the case of environmental regulation in China, the promulgation of documents was verified as the most effective method to signalling central government’s intentions about environmental regulation. The credibility, intensity and (targets of regulation) clarity of the documents can affect the recipients’ behaviors more effectively.(3) In the signaling chain with multiple links, the final transmission effect of the signal will be significantly affected by the intermediate links. (4) The combination of different signals could be more effective in some cases, for example, in regional governance. The research makes a supplement to the signaling theory. Also, it provides a solution to mobilize behaviors of signal receivers more effectively, solve the dilemma of environmental regulatory behavior of local governments in China, and narrow the green/environmental policy gap.