In the diploma thesis, we have analyzed and dimensioned the typical elements of R/C load-bearing structure of a commercial building. We have assumed that a four-story building is located in Domžale. We have determined the value of permanent and variable actions and the values of seismic load that affect the structure. The structure elements have been designed by the principles of limit states, according the Eurocode standard specifications. For the analysis of R/C floor plate and walls, two different idealized mathematical models have been built in software SAP2000. The result of design analysis, are the required amounts of reinforcement in the structural elements. We have designed the reinforcement of a floor plate and one selected wall, and presented them in the reinforcement plans.