探究（inquiry）是現代科學教育的重要核心，而探究學習活動會隨著開放程度有所不同，目標希望學習者有能力進行「開放式探究」（open inquiry）。科學展覽（Science Fair）是探究學習活動中最常見的開放式探究活動。然而，科展活動在台灣的教育現場面臨許多困難與挑戰，沒有經驗的教師無法有效引導學生進行探究活動，而且專業知能不足的教師無法建立學生對於科學展覽的概念。為了幫助科展探究的教與學，本研究主要的目有兩個，一為進行「網路科展探究系統」（Online Science Fair Inquiry System，OSFIS）的改版，以提供教師進行科展探究教學、學生進行科展探究所需要的各種鷹架；二為評估OSFIS是否能符合科展教師的需求。本研究研究對象為61名國小教師，採用調查研究法的問卷調查法，評估國小教師對於OSFIS的感知。研究結果發現現場國小教師對於OSFIS的「使用意願」、「整體知覺有用性」、「整體知覺易用性」、「探究歷程架構之有用性」、「鷹架功能之有用性」都是給予正面回饋；此外更進一步分析，發現在不同專業背景、不同網路教學經驗、在網路教學環境中的自我效能程度與對學生表現的信心程度可能會有影響科展教師對於OSFIS的感知。;Science fair inquiry (i.e., doing science fair projects) is one of the most common open inquiry learning activities in schools. By doing science fair projects, learners can develop their ability necessary to do scientific inquiry as well as understanding about scientific inquiry. However, there are a great deal of difficulties and challenges for the elementary teachers in Taiwan, such as they may not have sufficient professional ability in guiding learners to conduct science fair inquiry activities effectively. To scaffold teachers’ instruction and students’ learning in science fair inquiry, the “Online Science Fair Inquiry System” (OSFIS) was developed in this study. After the development of the OSFIS, a series of system evaluations on it was conducted with questionnaire survey. The participants of the system evaluation in this study were 61 elementary school teachers. In general, the participant teachers expressed satisfactory perceived usefulness and ease of use of the OSFIS, and were highly tended to use the OSFIS in their science fair instruction. Also, they recognized the usefulness of both the instructional and learning scaffoldings provided in the OSFIS. Moreover, this study revealed that the teachers’ academic backgrounds, experience on using the Internet for teaching, and their self-efficacy may play roles in their perceptions of using the OSFIS. Suggestions and implications for educational practices, system design, and future research are also discussed in this study.