摘要:The 21st -century biology learning requires technology-based learning which is potential for improving students’ learning outcomes. This research aimed to examine the validity and effectiveness of web-based learning media on Archaebacteria and Eubacteria on the learning process. This web-based learning media was structured by using 4-D Thiagarajan model. The research was conducted at three SSHSs of Samarinda. The data were obtained from validators’ (media expert,material expert,and linguist),teachers’,and students’ opinion by using questionnaire;while the effectiveness was determined based on students’ test score and their response. The results showed that the web-based learning media was very valid with the average score from experts as high as 95.27%. Moreover,this media has been proven to improve the student’s cognitive learning outcomes (gain score 0.39) and well responded by both teachers and students..