The purpose of this study is to create and assess the local context-based instructional model of the Twenty-First Century career skills development for primary students in the NangLae sub-district, Chiangrai Province. The methodology was divided into two steps: 1) Creating and examining the quality of the model and 2) Implementing and assessing the model. The samples were fifteen educational stakeholders, twelve teachers, and eighty-two students in the NangLae area. Research instruments included 1) the local context-based instructional model, 2) the evaluation checklist of the Twenty-First Century career skills for the students, 3) the checklist of student attitudes towards the model, and 4) the checklist of teachers’ opinions on the model implementation. The data were statistically analyzed using the mean, standard deviation, and t-test. The results of the study were as follows: First, the instructional model was sorted into five stages: 1) Context Introduction, 2) Information Searching, 3) Action, 4) Learning Discovery, and 5) Reflection. Besides, the model was approved and highly rated by educational experts. The average score of the validity was 4.57, with entirely feasible. Second, the model could enhance the students with Twenty-First Century career skills. Third, the students had rather high positive attitudes toward learning. Lastly, the teachers mostly agreed that the learning collaboration among the students was the key factor for developing students’ career skills.