Database design methods and tools have been investigated in the paper. The action diagram construction process has been investigated and three data design methodologies IDE1X, IE and Chen‘ have been considered. The main definitions have been described and classified in detail. The problems of database design have been stated and table normal forms have been presented. The company‘s employee income tax database model has been designed on the basis of the theory. Four step Chen‘s diagram has been used to design the data model. The company‘s employee income tax database has been designed and implemented in MS Access environment. The data import program from MS Excel has been developed.