The aim is the development of a new multi-level model of fuzzy semi-structured information data storage. A distinction of the proposed model from known is the use of extended polybasic intuitionistic sets for description of fuzzy data and representation of fuzzy attributes on three typing levels. The main result is formal description of fuzzy semi-structured data storage. To verify the result an example of application the developed model of data storage in the intellectual diagnostic decision-making system for railway transport is showed.