This study was conducted to determine the influence of Inquiry learning model on student's scientific attitudes in ecosystem material at MTs (islamic junior high school) Daarul Hikmah Sei Alim Asahan. The research method used was quasi experiment with 3 randomly determined classes sample taken by cluster random sampling technique. The research instrument used was a questionnaire of scientific attitudes related to the ecosystem. Data analysis technique used was Covariat Analysis at significant level α = 0.05 with the help of SPSS 22. The results showed there was significant influence of learning model on student's scientific attitude which taught by guided inquiry model (average 77.60), it significantly higher than modified free inquiry model (average 63.80) and conventional learning model (average 48.27). As a follow up,based on the results of this study, teachers expected to be able to apply guided inquiry model in ecosystem topics as an effort to improve student's scientific attitudes.