This study aims to design, develop and evaluate netiquette curriculum for junior high school students in Taiwan. Based on "Systematic Instructional Designing Model" and problem-based learning (PBL) as instructional strategy, this study developed three netiquette curriculum units and evaluated them formatively. Base on literature reviews, this study first explored the definitions, categories, concepts, concrete behaviors, general issues, and instructional strategies of the netiquette. This study also interviewed teachers and developed "Netiquette cognition and behavior questionnaire" for junior high school students. After the field test of the curriculum units, the results indicated that students reached 93% pass-rate in their cognitive test, and students' posttest scores were significantly higher than their pretest scores. In affective aspect, students' feedbacks showed that they paid attention to the instruction, felt interests in the topics, and agreed with the usability and importance of the netiquette. Regarding PBL, about 80% students enjoyed the PBL process and reached PBL goals. Finally, discussions and future research directions were also provided.