Incorporating computer science (CS) into K-12 education has been highlighted in recent years as an important way to promote computational thinking skills. The aim of this study was to investigate teachers' experiences with a new CS curriculum and address challenges to teachers during implementation. This study was designed to evaluate CS curriculum implementation in order to inform CS practices. Interview and survey data were collected and analyzed. Findings showed that teachers had high confidence in teaching CS; however, they sought professional development to acquire content knowledge and instructional strategies to effectively engage students in learning. As for the curriculum and students, the scope of the curriculum needed to be adjusted along with students' prerequisite skills and knowledge. As for the context, some schools did not have appropriate facilities. Recommendations for implementing CS curricula and implications are discussed.