The paper tries to make a summary of the researches (regarding the topic, the main question and the method as well) that focus on the analysis of different social categories/segments in Romania after the system change from 1989. It presents the types of questions that have been raised and the answers to them. Besides the 'What do we know?' type of questions there are also 'What we don't know?' types, which drive us to further, yet not discussed ones, to unused methods and views in the given research topic. The paper presents the above mentioned topics in two steps: first sketches questions and problems related to the segments of the social structure (i.e. entrepreneurs, the new middle class, working class and poverty groups), second on the social structure as a whole.