This research aims to analyze the concept of culture in the thought of Martyr Sayyid Muhammad Baqir al-Sadr (may God have mercy on him) and answer the question of what is the nature of culture in his intellectual system and how can its definition be reconstructed. The research method is conventional qualitative content analysis. The corpus of the research includes the written works of Martyr Sadr (may God have mercy on him), which were selected purposefully and until theoretical saturation was achieved, and the unit of analysis was also considered "subject". The findings showed that the concept of culture in his thought can be reconstructed through correlated concepts such as "ground", "belief", "concepts", "emotions and feelings", and "temperament". These concepts, in the form of intermediate categories, introduce culture as an internal and stable structure that originates from fundamental beliefs, is established in the form of concepts and emotions, and gives direction to individual and social behaviors. Accordingly, culture is an interwoven set of beliefs, perceptions, and emotions that are institutionalized in the minds of individuals as habits and provide the basis for the realization of the social school. The innovation of the research is in providing an inductive definition of culture based on a systematic analysis of the works of Martyr Sadr and explaining culture as a meaningful context and a condition for the realization of the Islamic social system.