The purposes of this study were (1)to analyze a set of criteria suitable for evaluating the quality of children's learning web sites, (2)to develop an evaluation instrument of children's learning web sites; (3)to provide elementary school teachers a guideline for selecting or filtering appropriate learning resources from Internet, and to provide website designers some suggestions to implement excellent children's learning web sites in the future. This study used both quantitative and qualitative methods to collect data 18 studies about website quality evaluation criteria from 1997 to 2000 were reviewed An instrument, called "Children's Learning Web Site Quality Evaluation Form", was developed and 244 elementary school teachers who have had experience on using web sites were the main subjects of this pilot study. The research results found that there were five dimensions of evaluation criteria as elements of evaluating quality of excellent children's learning web sites, including 48 items classified as website background description (5 items), multimedia features (7 items), interface design and structure (14 items), content (13 items), feedback and support (9 items).