Firstly, this dissertation analyses the current principal theory about m & a existing in the west countries . those who agree with m & a think that it can improve enterprise's efficiency, produce synergy effect, reduce operating risk and enlarge market share . while those who suspect m & a think that may be the representation of manager self-conceit and utility maximation, and it could enhance agent costs 本文首先从正反两方面分析了西方学者关于企业并购的主要理论，对于赞成并购的学者来说，并购可以提高企业效率、产生协同效应、降低经营风险、扩大市场份额；而对并购持怀疑态度的学者则认为，并购很可能是管理者盲目自大、追求自身效用最大化的表现，并购活动会提高企业的代理成本。
As a important incentive mchanism, executive stock option ( hereinafter short for eso ) has got a wide and successful application in the west countries . in recent years, this system has been introduced by some of our enterprises . they hope that this system can successfully solve our enterprises problem of inspiring managers, which has not solved in the past over 20 years reformation . a distinctive feature of modern enterprise is the seperation of the ownership and the managership 作为一种重要的激励机制，经营者股票期权(executivestockoption，以下简称eso)在西方国家得到了广泛而成功的应用。近年来，我国一些企业也纷纷引入eso制度，希望通过该制度来有效解决我国企业经历了20多年的改革却仍未从根本上解决的经营者激励问题。
