本文通过两个模型分析了在不存在保荐人和存在保荐人的情况下，证监会的事后惩罚力度与上市公司作假行为之间的关系。我们的分析发现，公司的作假行为与证监会事后的处罚力度、事后被市场发现的概率呈反向关系，而与公司发行的流通股的比例、公司上市的预期收益呈正向关系。保荐人与企业的合谋行为与证监会事前的监督力度、事后的处罚力度和事后被市场发现的概率呈反向关系，而与公司发行的流通股的比例、公司上市的预期收益呈正向关系。 Abstract: This article builds two models to show the relationship between ex post regulatory punishment and the forgery of listed companies. We show that the more severe the ex post regulatory punishment, the less forgery of listed companies, and the larger the probability of the forgery to be found by market, the less forgery, the larger the share of out equity, the more forgery, and that the more expected returns by forging, the more forgery, too. The probability that the advisor to collude with the forgery company is also affected by the severeness of the regulatory punishment, the probability of the forgery to be found by market, the share of out equity and the expected returns by forging. Ex ante supervision to advisor by regulatory agency is good to reduce the probability of the collusion between advisor and the forgery companies.