The purpose of this study was to determine the feasibility of science literacy based pocket books for fifth grade elementary school students. This research method refers to the Borg band Gall theory, using ten stages of research, namely information gathering, research planning, initial product development, field testing, revision, product testing, revision of field product testing results, validation, final improvement, and implementation. The data collection techniques used were observation, interview and questionnaire techniques. Sources of data in this study were fifth grade students and teachers in Rembang Regency. The design of the pocket book development is based on scientific literacy developed by the researcher, consisting of 3 parts, namely introduction, content, and closing. In the content section, the material integrates 4 aspects of scientific literacy. Product feasibility is seen from the validation results of material experts and linguists. From the material expert validation process obtained an average result of 3.33 with a percentage of 83% and very good category. The validation of linguists obtained results of 85% with an average of 3.40 and the category was very good. Based on the validation results, a scientific literacy-based pocket book is suitable for use as a companion book in learning.