Digitalization of well logging data is a time consuming process and it is required to be familiar with the geology of local area, geophysics and theory of well logging data that were measured in the boreholes. Primary task of master thesis is a transformation of analog well logging data into digital well logging data. Well logging measurements that were digitized are: caliper, density log, neutron log, microlog, laterolog, gama log, self potencial log, long and short normal induction log. Digitalization of well logging data was performed in three different computer programms. First program that was used is Get Data Graph Digitizer. With the following program you can determine the values of well logging data. These values are then arranged in computer programme Excel. With the Excel files finished or arranged, the digitalization can begin in Strater programme. Well logging data is interpreted in the mentioned programme, because the programme is easy to manage. The features of boreholes, well logging data and the geology of individual borehole are displayed in Strater. Layers vary from each borehole to borehole because of the various combinations of layers and that can effect on the measurements of each well logging data. Well logging data were acquired in the Coal mine Velenje from seven exploration boreholes. In the master thesis, 50 different analog well logs were digitized. Results of the digitilization is demonstrated in the programme Strater.