This research aims are (1) to investigate the quality of ‘English Alive’ textbook to teach reading skill for tenth grade of SMA Trensains Muhammadiyah Sragen; and (2) to develop reading-based supplementary materials to teach reading skill for tenth grade of SMA Trensains Muhammadiyah Sragen. This Research and Development study were conducted in 2 stages; exploration and model development. Exploration stage consists of need analysis, library research, prototype design, and expert judgment while model development consists of prototype try out and evaluation. 
It was showed in the result of need analysis that ‘English Alive’ has some weaknesses in teaching reading skill; partially compatible aim, missing of scientific content, limited reading material, lack of teaching reading methodology, and lack of teacher guidance. To develop supplementary materials, “English Alive” was evaluated using a construct of a good textbook evaluation. The result shows that it has several weaknesses in term of aims, content of language, skills, methodology, and teacher’s guidance. Therefore, there was a need for developing supplementary reading material. 
The data of this research was taken from English teacher, tenth grade students of SMA Trensains Muhammadiyah Sragen, syllabus and English Alive. The data was taken using interview, questionnaires, observation, documenting, expert judgment, and Focus Group Discussion. Then, the data was reduced, displayed, and concluded based on Miles and Huberman’ model. 
The prototype of content-based reading material are developed based on Curriculum 2006 by analyzing standard competence of scientific subjects in Curriculum 2006. Then, some materials which meet those standard competences are developed into draft using teaching reading procedure. The draft was taken to be evaluated by the ELT expert and science expert to find the weakness of the prototype. The draft was revised using experts’ feedback. Then the materials are taken into try-out once to validate the feasibility. 
This content-based reading material is hoped to be additional materials for teaching reading and able to improve students’ motivation and classroom situation during its application. 
Keywords: Reading-based, Supplementary Materials, Content Based, English for Science