Masonry as a material is much more resistant to compressive loads than tension and shear loads. Earthquake is the most common shear load that can affect masonry buildings. Seismic activity in Slovenia is very high. That is why it is extremely important to properly asses the shear resistance of masonry buildings. Detailed rules for determining load carrying capacity of building and civil engineering works in masonry are given in part 1-1 of standard Eurocode 6: Design of masonry structures – Part 1-1: General rules for reinforced and unreinforced masonry structures (SIST EN 1996-1-1, 2006). Standard Eurocode 6 does not define any standard tests for determining shear strength of masonry structural elements. It provides empirical equations which are based on failure mechanisms of masonry elements. A new proposal of part 1-1 of standard Eurocode 6 (prEN 1996-1-1, 2018) is in preparation. One of the adjustments regarding shear strength of masonry elements relates to the characteristic coefficient of friction ^^, which appears in the equation for calculating characteristic shear strength of masonry elements ^^^. In the current standard Eurocode 6 (SIST EN 1996-1-1, 2006) the value of the characteristic coefficient of friction ^^ is prescribed, however the new proposal of the standard Eurocode 6 (prEN 1996-1-1, 2018) provides recommendations so that the value can be defined as a national parameter. In this graduation thesis the value of the characteristic coefficient of friction ^^ is determined from the data bases of the results of various alternative shear tests done on masonry walls specimens at the Faculty of Civil Engineering, University of Ljubljana and at the Slovenian national building and civil engineering institute (ZAG). The results of ^^ calculations are different for Groups 1 and 2 units. For masonry made with group 1 units with 0 % volume of the holes with strict safety requirements values ^^ = 0,3 or ^^ = 0,35 are appropriate. Whereas for group 2 and group 1 units with 25 % volume of the holes value ^^ = 0,4 is on the safe side.