中文摘要：

采用中小企业板上市企业财务数据，构建非平衡面板数据模型，检验货币政策变动对中小企业融资约束及投资效率的影响。研究表明，宽松的货币政策可以有效缓解中小企业融资约束，而且相对于国有中小企业来说，宽松的货币政策对民营中小企业融资约束的缓解作用更大。进一步，当货币政策宽松时，面临高投资机会和低投资机会的中小企业的投资效率都得到了显著地提升；并且宽松的货币政策可以缩小国有中小企业和民营中小企业投资效率的差距。本文的政策含义在于，今后我国货币政策制定，应根据不同微观经济主体的特征，更多的采取“定向调控”的货币政策，以期使政策发挥最大效用，进而促进中小企业健康成长和经济持续发展。

英文摘要：

Using financial data of Small and Medium Enterprises board listed companies, constructing an unbalanced panel data model, this paper examines the effects of monetary policy changeson financing constraints and investment efficiency of Small and Medium Enterprises. The results show that easy monetary policy can alleviate financing constraints, and this effec on private Small and Medium Enterprises is greater than state-owned Small and Medium Enterprises. When monetary policy eases, investment efficiency of Small and Medium Enterprises faced with high investment opportunities and low investment opportunities is significantly improved; and easy monetary policy can narrow the investment efficiency gap between private Small and Medium Enterprises and state-owned Small and Medium Enterprises. Policy implication of this paper is that regulator should take ＂targeted regulation＂ monetary policy in future based on the characteristic of different micro-economic subject, thereby promoting healthy growth of Small and Medium Enterprises and sustained economic development.