The objectives of this study are: 1) to study problems and the needs in community-based transdisciplinary learning for social studies teachers in the diverse school contexts, Northern of Thailand 2) to develop and find the efficiency of handbook of community-based transdisciplinary learning for social studies teachers in the diverse school contexts, Northern of Thailand and 3) to examine the implementation results of the handbook. This research is based on the research foundation of a mixed method in education research. The population involved in this study included 1) educational connoisseurship of area-based who are selected by means of purposive sampling, from not less than 5 persons and 2) social studies teachers in the Northern-region provinces of Thailand who are selected by means of accidental sampling, from not less than 334 persons. The research instruments are: 1) a questionnaire on problems and the needs in community-based transdisciplinary learning 2) an appropriateness assessment form on the handbook and 3) an evaluation form of teacher professional competence in community-based transdisciplinary learning. The qualitative data are analyzed and shown on content analysis and descriptive analysis. The quantitative statistics employed for data analysis are mean and standard deviation through statistical program. The research findings revealed as follows; 1) Problems and the needs: teacher professional competence needs to be improved in community-based transdisciplinary learning through 7 skills, namely; Integrated learning Management, Technology Integrated Learning, Integrating Ethics Learning, Community Resource Management, Transdisciplinary Innovation Integrated Learning, Creative Educational Measurement Design, and Competency of Networking skill. 2) The result of handbook development: "SOCIAL Action Learning Model", includes 6 steps, should be implemented in community-based transdisciplinary learning for social studies teachers. Due to the evaluation of the handbook, the result is at the highest level of appropriation ([x-bar]= 4.58, S.D. = 0.57). 3) The result of handbook using: the handbook of community-based transdisciplinary learning for social studies teachers found the evaluation result at a high level ([x-bar]= 3.96, S.D. = 0.89)