公司风险承担是确立公司竞争优势，推动经济增长的关键因素。与现有研究集中于大股东的性质等静态特征上研究公司风险承担不同，本项目从大股东动态调整投资组合的视角考察大股东股权质押行为对公司风险承担的影响。本项目综合运用公司财务、公司治理的理论方法，首先考察大股东股权质押影响公司风险承担的机理；其次研究公司债务政策选择对二者相关性的影响，形成促进公司合理承担风险、抑制过度风险承担的最优债务契约设计；最后基于大股东股权质押下适度提高风险承担与过度风险承担对股价波动风险的不同影响，构建风险评价与预警模型。本项目的研究不仅有助于拓展公司风险承担的理论研究视角，而且对于债权人保护自身利益，中、小股东构建投资组合分散风险具有重要的现实意义。本项目强调理论与现实相结合，在探讨理论规律的基础上，结合现实需求，设计大股东股权质押条件下最优债务契约与风险监控预警模型，预期成果不仅具有学术价值，也具有一定的应用前景。

Corporate risk-taking is one of the critical factors to strength competitive advantage, and to promote economy. Prior studies focus on the relation between risk-taking and other static factors like large shareholders concentration, and this project studies the effect of large shareholders’ stock pledge on corporate risk-taking based on the fact that large shareholders dynamically modify their investment portfolio. To begin with, based on the theory of corporate finance and corporate governance this project analyst the mechanism of how large shareholders’ stock pledges affect corporate risk-taking. Then we studies how the debt policy influence the relation between large shareholders’ stock pledge and corporate risk-taking, through which we can find out the optimal design of corporate debt covenants that promote moderate risk-taking but reduce excessive risk-taking. At last, we can build model of risk evaluation and risk early-warning on the different impacts on the stock price volatility by excessive or moderate risk-taking increase resulted from large shareholders’ stock pledge. This program expands the risk-taking theory research and has great significance on creditor protection and diversification of minority shareholders. This program emphasizes the combination of theory and practice, and on the basis of theory meets the practice demand, through which we can design the optimal debt covenants and risk early-warning model under large shareholders’ stock pledge. The result of this program has not only academic but also practical significance.