The purposes of this research study were: 1) to analyze basic information of research concerning Web-Based Instruction 2) to analyze effect sizes form factors effecting students learning results in Web-Based Instruction (WBI) and 3) to synthesis findings appropriated to learning results in Web-Based Instruction (WBI).Based on meta-analysis approach along with basic framework of Web-Based Instruction (WBI).The studies analyzed 147 experimental research published during years 2005-2010. According there were 139 effect sizes with the 21 variables. The results of research were: 1. Based on research in Web-Based Instruction published during years 2005-2010, year 2008 was found as most published (25.2%), the institution produced research study most was Chulalongkorn University (25.2%), and the level of research studies mainly were thesis in master’s degree (78.2%). 2. The research has enough information to examine is 116 experimental research; studies there were 139 effect sizes with the 21 variables. The mean overall effect size of research, effecting learning results of students in Web-Based Instruction at high level ( 2.77). 3. The synthesis factor to develop of learning results in Web-Based Instruction (WBI) from meta-analysis approach along with basic framework of Web-Based Instruction (WBI) consisted of 3 major factors: 1) Factor of pedagogy, research found that instruction along constructivist is most popular used in Web-Based Instruction, which Influence the develop of learning results at very high level, 2) Factor of content, found that is used content in science is most popular used in Web-Based Instruction, which Influence the develop of learning results at high level, and 3) Factor of technology concerning Learning Management System technology, the use of Web Authoring tool (Adobe Dreamweaver) is most popular used in Web-Based Instruction, which Influence the develop of learning results at high level. Concerning courseware technology, it was found that the use of e-documents is most popular used in Web-Based Instruction, which Influence the develop of learning results at rather high level. Concerning communication technology, it was found that the use of webboard is most popular in Web-Based Instruction, which Influence the develop of learning results at rather high level, Concerning evaluation technology, it was found that the use of online test/quiz is most popular used in Web-Based Instruction, which Influence the develop of learning results at rather high level.