Given the fact that there is vast literature with regards to political legitimacy, this research is conducted to show the construction of a paradigm of political legitimacy of certain kind from the perspective of the traditions received from the Infallibles by referring to al-Kafi drawing upon a new method called grounded theory. To do this, direct reference is made to the relevant traditions as the documents and research data, and a conceptual framework (conceptualizing) is used on the basis of both connotation (signification of complete accord) and implication (signification of partial accord) in three stages of coding (open coding, axial coding and selective coding) which result in constructing a paradigm of political legitimacy from the viewpoint of traditions. Based on this, political legitimacy is taken as the axis and nucleus of this paradigm around which the conditions (causal, intervening, grounded) and action theory revolve and gain their significance. Having analyzed the data on the political legitimacy, the research shows that the stability and instability of political system gains its significance in terms of political legitimacy.