中文摘要：

基于高阶梯队理论构建研究模型并提出研究假设，并以机械设备行业105家更换过CEO的上市公司作为研究样本，检验新任CEO特征以及TMT异质性的调节作用对企业绩效改善的影响。研究表明，新任CEO的学历水平显著负向影响绩效改善，TMT年龄异质性和任期异质性负向调节新任CEO学历水平和专业教育背景与绩效改善之间的关系，TMT异质性正向调节新任CEO的MBA教育背景与企业绩效改善之间的关系。

英文摘要：

This article makes use of a sample of 105 listed mechanical companies that experienced change of CEO to investigate whether the characteristics of new CEO impact on the improvement of corporate performance and how the TMT heterogeneity moderate the relationship between them. It is shown that new CEOs＇ educational levels and improvement of corporate performance are negatively related; and that both TMT age heterogeneity and tenure heterogeneity have a negative moderating effect on the relationship between new CEOs＇ educational and professional backgrounds and improvement of corporate performance, while TMT heterogeneity has a positive moderating effect on the relationship between new CEOs＇ MBA educational backgrounds and improvement of corporate performance.