This study aims to present ways of implementing inquiry - learning model with the use of scientific reports to improve teachers’ understanding and ability on teaching biology at secondary level. The quantitative research method is quasi-experiment design with pre-test and post-test control group. The research instrument for collecting data of students’ higher order thinking skills is scoring rubrics for assessing abilities on developing and presenting a scientific report. The instruments for assessing teachers’ skills are teacher observation sheets over inquiry -based learning scientific report using an induction method. The research subjects consist of 4 biology teachers and 80 of grade 10 students from Public S econdary S chool 3 Samarinda. The teachers are all female; while from 80 students, 53 of them are female and the rest 27 are male . The students’ age ranges from 16 to 18 years old . The research lasted for 1 month. Analysis of data uses t test, that if t_outcome is higher than t_table, the inquiry -based learning model using scientific reports does affect students’ higher order thinking skills . Data analysis is composed in tabulation format with several graded categories: inadequate , sufficient, good and excellent. The result of the study is that higher order thinking skills of students are increasing in numbers and more equal compared with classes taught by teachers who d id not follow the inquiry -based learning model workshop and presentation. The inquiry -based learning model was applied via preparation and presentations of scientific reports after the students carry out practical activities through the guidance of student activity work sheets.