摘要:AbstractIn high school, the concept of the phenomenon of plate tectonics is considered as a basic construction in the understanding of the geology.Based on the conviction that conceptions are a major focus in the teaching-learning process, making a diagnostic of representations of students about the phenomenon of plate tectonics is essential.The target population is a group of students all belonging to the science section at the last year in high school, and we use the questionnaire as a working tool.The results obtained during this project allowed us to highlight the following conclusions: • Students assemble conceptions that are influenced by their socio-cultural and religious surroundings in order to explain geological phenomena and especially phenomena related to plate tectonics.• Students use a reductionist approach in their explanations, which confirms our research hypothesis on barriers that can be created in relation to the concept of prior-knowledge.• Several conceptions were located through this study: students confuse several concepts. Hence, such process generates several obstacles and subsequently hinders the assimilation of concepts related to plate tectonics. • Some students still keep conceptions they had before learning about the concept of plate tectonics in junior-high school. Thus, our second assumption may be valid and teaching in this case is based on cheer copying which favours a momentary learning that will soon be forgotten.Concept evaluation remains a fundamental tool so that to comprehend the origin of the obstacles faced by students while their learning of the concept of plate tectonics.