隨著資訊與通訊科技的發達，電子化政府隨之興起，政府開始利用資訊與通訊科技服務民眾。對電子化政府而言，其面臨的顧客不只包含外部顧客─公民與企業，也包含一大群的內部顧客─公務人員，由於公務人員是電子化政府重要的內部顧客，了解他們對於電子化系統、服務的使用感受有其必要性，也顯現G2E計畫成效評估的重要性。有鑑於政府採購為國家龐大支出，因此，本研究以政府電子採購網作為研究的個案。 本研究回顧電子化政府計畫評估、顧客導向的電子化政府、顧客滿意度的影響因素三類文獻，並結合Heeks (2006)電子化政府價值鏈、DeLone & McLean資訊系統成功模型，以及朱斌妤(2010-2013)的G2E計畫指標，從內部使用者角度發展電子採購內部顧客成效評估因果模型，主要由六大構面組成，分別為組織管理、服務品質、系統品質、資訊品質、員工感受效益以及員工滿意度，並透過次級資料進行驗證。 研究結果發現，本研究提出的電子採購內部顧客成效評估因果模型具有一定的解釋力，各構面之間的影響關係皆達統計上的顯著。本研究也比較不同機關性質與標案性質，進行不同構面之間的路徑係數比較，結果顯示不同的機關性質、標案性質對於不同構面之間的路徑係數確實有影響，根據研究結果，本研究也提出了一些政策建議與後續研究的建議。 / Electronic Government (e-Government) is about governments interacting, conducting business and delivering services to their citizens and private companies electronically through the use of Information and Communication Technology (ICT). All key stakeholders including the government employees, private sectors, and citizens benefit from successful implementation of ICTs. The usage evaluation from e-government employees’ point of view (G2E), i.e., the internal customers of e-government, is vital. This research uses Government e-Procurement System as a case study of G2E program evaluation. Topics of literature review for this research include e-Government programs assessment, customer-orientede-Government and influencing factors of customer’s satisfaction, combines with Heeks’ e-Government Value Chain, DeLone and McLean’s Information System Success Model, and Chu’s G2E programs assessment indicators, which propose a casual model for internal customers’ evaluation of e-Procurement system in Taiwan. This model consists of six dimensions－organization management, service squality, system quality, information quality, employee perceived benefits, and employee satisfaction. The outcomes of this research indicate that our model is strongly supported by the empirical data. This research also includes comparations of different organizations and procurement cases, which indicate that different organizations and procurement cases have difference in path coefficients. Finally, this research makes some suggestions for the improvement of e-Procurement policy, and for future researches.