The structural design standards Eurocodes will become obligatory in Slovenia from the beginning of 2008. The main focus of the diploma thesis is the Eurocode 8 standard for earthquake resistant design of structures. More specifically, the computer program is developed for determination of the behaviour factor, the design response spectrum, the fundamental period of the structure according to simplified procedure and for determination of the seismic design forces according to lateral force method of analysis. The program is made in Excel by emplying Visual Basic Editor. Firstly, the procedure for determination of behaviour factor and design response spectrum is explained for different types of structures, then, the algorithms for program are developed and implemented and at the end for examples are presented. In the first example we have tested the program by an example of multi-storey building. The second example was a comparison between different structural types. We have seen that the lowest seismic loading is foreseen for frame structural types. Third example was a comparison between low (DCL), medium (DCM) and high (DCH) ductility class. It is shown that for selected case the design seismic forces for DCH ductility class are for 50% lower in comparison with the design forces for DCM ductility class and 300% lower than DCL ductility class. DCM ductility class is for 167% lower than DCL ductility class. Based on our fourth example we found out that the most appropriate ground for earthquake resistant buildings are grounds type A
