在全球化趨勢之下，企業所面臨的環境變化快速，而其生存與致勝之關鍵在於提昇競爭優勢，同時因為高科技的蓬勃發展與資訊科技的應用普及，已使資訊服務產業成為全球最重要的產業之一，不僅本身市場商機龐大，更攸關其他產業競爭力提升與否的問題，因此世界各國無不爭相投入巨資發展資訊服務業其競爭優勢。因此，本研究探討需求管理對於專案績效之影響並了解不同專案類型之需求管理程度是否具有顯著差異。 針對108份國內資訊服務業填答有效問卷進行資料分析，結果發現，需求管理對專案時程、成本、品質具正面影響，專案需求精確性、確認性對專案效益影響；另外研究亦發現，專案複雜度比低度專案複雜度低有顯著差異及中、高度專案團隊的合作關係比低度專案團隊的合作關係高度有顯著差異。針對上述結果，本研究提出理論意涵與管理建議。 Under the trend of globalization, the enterprises are facing rapid environmental change and the key to survival and success is to enhance competitive advantage. Meanwhile, the development of the high tech and popular of the information tech result in the information service has become one of the most important industry. It is not only huge market opportunity, but be also relevant of the increasing the competitive of the other industry. The phenomenon causes the industries of the world invest to develop the information heavily to obtain competitive advantage. Therefore, the study explores the effect of demand management on the project performance and to figure out the significant difference of the demand management degree of project types. Data was collected from the 108 valid questionnaires of the domestic information service personnel. The results show that demand management had positive effects on project schedule, cost, and quality. Accuracy and confirmation of project demand had positive effects on project efficacy. Also the recovery higher project complexity was found that had significant difference from the lower project complexity. Higher project cooperation relationship had significant difference from the lower project cooperation relationship. Both theoretical and practical implications are discussed.