This research aimed to produce a set of science teaching and learning material that is feasible to facilitate student’s science process skills of Junior High School. It consists of syllabus, lesson plan, student’s worksheet, instructional media, and evaluation sheet to measure student’s science process skills. The research was conducted to implement it based on guided inquiry model. It was developed using 4-D model i.e. define, design, develop and disseminate which are tried out using one group pre-test post-test design. It was conducted to 40 eighth grade students in SMPN 4 Kepil, Wonosobo. The data were collected using validation, observation, test, and questionnaire method. They had analyzed using descriptive quantitative and qualitative technique. The results showed the set of teaching and learning materials developed are valid, practical, and effective to improve student’s science process skills. It can be concluded that the set of learning materials developed is feasible to facilitate the improvement of student’s science process skills in the guided inquiry learning.