[en] There have been four preferred sites for L/ILW repository selected in the siting program in Croatia so far. According to the accepted and verified site selection procedure, these sites are suitable for a more detailed characterization, including also site specific field investigations. The aim of these investigations is to measure and calculate all needed site specific parameters important for performance of safety assessment, aiming eventually with selection of the final disposal site. Both Croatian and IAEA regulations referring to radwaste repository siting procedure have been briefly discussed. Detailed site investigations foreseen to be done in order to perform a successful site characterization, refer to the following main topics: geomorphology, lithostratigraphy, tectonics, seismicity, rock mechanics, surface-water hydrology, aquifer features and groundwater hydrology, rock and groundwater chemistry, and radionuclide transport modeling. All these issues are listed in suggested site characterization format. (author)