日落条款作为特别表决权制度的重要退出机制，通过事前威慑、事后救济的方式能够在维系特别表决权制度正当性基础的同时约束特别表决权股东滥用控制权的行为，成为现行各国适用特别表决权制度的核心配套措施。日落条款一般可以分为时间型日落条款和事件型日落条款。时间型日落条款是指特别表决权制度在公司章程设定的固定期限届满后终止。事件型日落条款是指当发生公司章程设定的非期限型事件时，特别表决权股份部分或者全部转换为普通股。而根据特别表决权股东持股资格、持股比例、持股行为等具体事由，事件型日落条款又可以分为分离日落条款、稀释日落条款和转让日落条款。相较于时间型日落条款“一刀切”的野蛮终结方式，事件型日落条款更具有针对性，也更为灵活与温柔，在证券交易所与上市公司中得到了广泛适用，具有更大的实务研究价值。然而我国现行事件型日落条款规则依然存在较大的争议，主要集中在分离日落条款的特别表决权股东资格的设定、转让日落条款的转让行为和转让豁免对象、稀释日落条款的稀释股权比例。

针对上述问题，笔者通过特别表决权制度内部机理以及外部因素的分析，认为日落条款应当基于特别表决权制度的代理成本问题和正当性基础两个内部视角以及证券交易所竞次竞争和投资者保护两个外部因素进行完善。就分离日落条款而言，首先，法人或者其他组织担任特别表决权股东具有现实的商业价值与需求，有提升利于证券交易所竞争力，但又不可否认法团主体容易形成金字塔结构及股权代持问题，导致现金流与表决权进一步背离。但此类问题在我国目前上市审核环境下能够得到一定程度的抑制。因此笔者认为应当允许法人或者其他组织担任特别表决权股东。其次，特质愿景与人力资本价值的实现需要特别表决权股东以董事身份持续参与经营，而且特别表决制度下董事会成为实质决策中心，董事身份在公司决策中发挥着举足轻重的作用，同时董事身份也能带来独立董事的监督与董事义务的约束，抑制代理成本。因此特别表决权股东应当担任公司董事，且在共同控制的情形下只需要委任一名董事代表。最后，业绩是特质愿景与人力资本价值的实现形式。设定业绩资格具有合理性，但是由于业绩资格影响公司股权的清晰与稳定，在实务中适用难度较大，因此业绩设定应当符合监管要求，不宜与股权直接绑定，业绩标准不宜严苛，业绩资格也不宜强制要求适用。就转让日落条款而言，首先，股权转让行为应当涵盖某项或者多项权利转让，对于委托表决应当限定在商事便利的范畴。其次，股权转让的豁免对象可以依据对于特质愿景和人力资本的破坏程度分成三种情形：第一，特别表决权股东控制的持股主体应当豁免转让；第二，其他特别表决权股东的豁免转让应当在招股说明书中事先披露，在发生转让行为时应当经过同股同权股东大会的同意；第三，除上述以外的第三人应当禁止转让。就稀释日落条款而言，首先，现行上市规则下稀释比例关注的是特别表决权股份数与全部股份数比例，此时稀释比例受到普通股的影响，但是普通股的变化往往是因为股权激励、收购公司、扩大生产等出于正当经营目的融资行为产生，这些被动稀释的情况不应当受到限制与惩罚。因此，稀释比例更应当关注的特别表决权股份自身的变化，一般为特别表决权股份持有比例或者出售比例。如果是特别表决权股东主动减持特别表决权股份导致的稀释，这意味着特别表决权股东在主动减小与公司利益关联性，此时应当触发日落条款。

As an important exit mechanism for dual-class share structure, the sunset clause can maintain the legitimacy of dual-class share structure while restraining the abuse of control by special voting shareholders through prior deterrence and post-remedy, and has become a common supporting measure for countries to apply dual-class share structure.Sunset clauses can generally be divided into time-triggered sunset clauses and event-triggered sunset clauses, time-triggered sunset clauses refer to the termination of the dual-class share structure system after the expiration of the fixed period set by the articles of association, event-triggered sunset clauses refer to the occurrence of non-term events set by the articles of association, special voting shares are partially or fully converted into common shares, and according to the specific reasons such as the shareholding qualification, shareholding ratio, and shareholding behavior of special voting shareholders, event-triggered sunset clauses can be divided into separate sunset clauses, Dilution sunset clause and transfer sunset clause. Compared with the "one-size-fits-all" barbaric termination method of time-based sunset clauses, event-triggered sunset clauses are more targeted, more flexible and gentle, widely used in exchanges and listed companies, and have greater practical research value, but China's current event-triggered sunset clause rules still have greater controversy, mainly focusing on the setting of special voting shareholder qualifications for separating sunset clauses, the transfer of sunset clauses and the transfer exemption objects, The method and scope of the calculation of the diluted equity ratio of the diluted sunset clause.

In view of the above problems, through the analysis of the internal mechanism and external factors of the dual-class share structure, the author believes that the sunset clause should be improved based on the two internal perspectives of the agency cost issue and legitimacy basis of the dual-class share structure, as well as the two external factors of stock exchange competition and investor protection. As far as the separation sunset clause is concerned, first of all, allowing legal persons or other organizations to serve as special voting shareholders has real commercial value and demand, and at the same time is conducive to the improvement of the competitiveness of China's stock exchanges, although this is easy to cause the problem of pyramid structure, resulting in further deviation of cash flow and voting rights, but such problems can be suppressed to a certain extent in China's current listing practice environment. Secondly, the realization of the special vision and human capital value requires special voting shareholders to continue to participate in the operation as directors, and under the dual-class share structure, the board of directors becomes the substantive decision-making center, and the status of directors plays a pivotal role in the company's decision-making, and the status of directors can also bring about the supervision of independent directors and the constraints of directors' obligations, and curb agency costs, so special voting shareholders should serve as directors of the company, and if more than one person serves as special voting shareholders, only one director representative needs to be appointed. Finally, performance is the realization form of characteristic vision and human capital value, and it is reasonable to set performance qualifications, but because performance qualifications affect the clarity and stability of the company's equity, it is difficult to apply in practice, so it is not appropriate to be directly bound to equity when setting performance, performance standards should not be strict, and performance qualifications should not be mandatory to apply. As far as the sunset clause of transfer is concerned, firstly, the act of equity transfer should cover the transfer of one or more rights, and the proxy vote should be limited to the scope of commercial convenience. Second, the exemption targets for equity transfer can be divided into three situations according to the degree of damage to the characteristic vision and human capital： first, the shareholding entity controlled by the special voting shareholders should be exempted from transfer; Second, the exemption of other special voting shareholders shall be disclosed in advance in the prospectus, and the consent of the general meeting of shareholders with the same rights shall be obtained in the event of equity transfer; Third, third parties other than the above should be prohibited from transferring. As far as the dilution sunset clause is concerned, first of all, the dilution ratio under the current listing rules focuses on the ratio of the number of special voting shares to the total number of shares, at this time the dilution ratio is affected by ordinary shares, but the change of ordinary shares is often caused by equity incentives, acquisition of companies, expansion of production and other financing behaviors for legitimate business purposes, and these passive dilution situations should not be restricted and punished, so the dilution ratio should pay more attention to the change of special voting shares themselves. Generally, the proportion of special voting shares held or sold in proportion should trigger the sunset if the reduction of special voting shares means that the special voting shareholders are actively reducing their interest relationship with the company.