This aims of research to determine the effectiveness of science textbooks based on Socio-scientific Issues to improve students creative thinking abilities. Creative thinking in 21st-century learning is very important and must be trained. Based on several observational samples, the average creative thinking ability of junior high school students is less optimal, especially for aspects of fluency, flexibility, originality, and elaboration. This may be because the textbooks used in learning have not optimally loaded content that trains creative thinking. This research uses the form of one group pretest-posttest design so that the N-Gain value is obtained, the results of which are used to represent the effectiveness of science textbooks based on Socio-Scientific Issues used on learning in biotechnology materials in junior high schools.