This study aims to: (1) develop thematic textbooks based on local wisdom of our best friend's environmental theme material for grade V elementary school students, (2) Know the validity, practicality and effectiveness of thematic textbooks based on local wisdom of our best friend's environmental theme material for grade students V elementary school. The development of thematic textbook learning media based on local wisdom uses the Research and Development (R & D) method. The development stages include: (1) Potentials and problems, (2) Data collection, (3) Product design, (4) Design validation, (5) Design revision, (6) Product testing, (7) Product revision (Sugiyono, 2016). The research was conducted with 33 students from class V SDN 2 Sendang Jepara Regency. Initial product development is a process of making media based on needs analysis. Expert testing or validation was carried out by 2 experts, namely media experts and material experts. The data collection method in this research is observation, interview, and questionnaire. The data analysis technique used descriptive analysis and comparison test of two independent groups, namely using the independent t-test. Based on the results of the trial, this thematic teaching material is very valid, very interesting, effective and can be applied in learning. This can be seen from the results of the validation test from three experts which show that the product is good. The results of the effectiveness test showed that the experimental class students had better learning outcomes than the control class. This means that textbooks based on local wisdom of Jepara Regency are developed effectively