本研究探討企業宣告私募股權之動機對宣告時之折價幅度、異常報酬，以及其後續的執行率與經營績效之影響。並將私募案依投資人加以分類，區分為積極性私募、管理階層私募與消極性私募，各類私募分開探討其動機、執行率與經營績效。 實證結果發現，企業選擇私募股權融資的動機如下：(1) 進行積極性私募之動機，並無法以監督需求假說解釋之；(2)自利交易為進行管理階層私募之動機；(3) 進行消極性私募之動機，並無法以控制權鞏假說解釋之。 私募實際執行與否的影響因素方面，實證結果如下：(1) 積極性私募因為研究樣本過少，無法進行實證分析；(2) 管理階層私募方面，當預計發行股數佔流通在外股數比例較高時，實際執行的可能性較高；(3) 消極性私募方面，投資機會於宣告後增加，實際執行的可能性較高，然而當內部人持股比例低於5%或高於25%時，實際執行的可能性較低。 至於私募之執行與後續經營績效之關聯性，實證結果發現：(1) 積極性私募由於研究樣本過少，無法進行實證分析；(2) 執行管理階層私募之公司，其經營績效於執行後確實獲得提升；(3) 執行消極性私募之公司，其經營績效於執行後確實獲得提升，然而此發現並不支持控制權鞏固假說之預期。 / This research mainly discusses the motivations of firms which announce issuing private equity. The announcement motivations will influence the price discount and abnormal returns in the period of announcement, wills to execute the private placement, and the subsequent performance of those announcing firms. This study classifies private placements into three groups, including active placements, managerial placements, and passive placements. There are different motivations, situations of executions, and subsequent performances in different types of private placements. The empirical results on the motivations of firms that announce issuing equity privately indicate the following: (1) Monitoring hypothesis can’t explain why firms issue private equity to active investors. (2) Managerial self-dealing is the purpose of firms issuing private equity to insiders. (3) Managerial entrenchment hypothesis can’t explain why firms issue private equity to passive investors. The empirical results on the factors that influence firms execute the private placement or not indicate the followings: (1) Because of the sample constraints, this study can’t analyze in what situation firms will execute active private placements. (2) For managerial placements, those with higher percentage of the firm’s outstanding common stock represented by the placement tend to be executed. (3) For passive placements, when the investment opportunities increased after announcements, firms tend to execute the placement. However, when the ownership concentration is less than 5% or higher than 25%, firms’ wills to execute the placement are weaker. The empirical results on the association between the execution of private placements and its subsequent performance indicate the following: (1) Because of the sample constraints, this study can’t analyze the impacts of the execution of the active placement on the subsequent performance of the announcing fitm. (2) Firms executing managerial placements tend to have better subsequent performance. (3) Firms executing passive placements tend to have better subsequent performance. However, managerial entrenchment hypothesis can’t explain this result.