Since the beginning of 21st century, Vietnam has achieved significant educational achievements, especially in the improvement of general education network and teaching quality. The reality has showed that working effectiveness of a school totally depend on the competence of its principal and of the entire teaching staff. Once these two entities meet the required capacities in the context of innovation in education, leadership and management, they will surely make an important contribution to the development of the school, fulfilling the long-term national goal of comprehensive innovation of Vietnamese education in the current period. In the article, the authors give first an overview on the concept of competence and then the necessity for "competence" of the principal and teachers in view of their roles in school development with an aim to further improving the quality of school management and that of teaching and learning in response to the motional cause of education innovation.