The density and kinematic viscosity of AgGaSe2 were investigated in the solid and liquid states in the temperature range 690 - 930 °C. Density and dynamic viscosity measurements were carried out using the thermometer method and the rotating cylinder method. Experimental data show that the dependence of viscosity on temperature has an activation character and that logarithm of viscosity vs. reciprocal absolute temperature can be approximated by two straight lines corresponding to activation energies 0.36 eV and 0.19 eV in the solid and liquid states, respectively. The temperature dependence of the free volume was calculated and it was found that it decreases linearly with temperature. The results are explained on the basis of the free-volume model.Istraživali smo gustoću i kinematičku viskoznost AgGaSe2 u čvrstom i tekućem stanju na temperaturama 690 – 930 ◦C. U mjerenjima gustoće i viskoznosti primijenili smo termometrijsku metodu odnosno metodu rotirajućeg valjka. Mjerni podaci ukazuju da ovisnost viskoznosti η o temperaturi ima aktivacijske značajke, te se ovisnost log η o temperaturi može aproksimirati pravcima koji odgovaraju aktivacijskim energijama 0.36 eV and 0.19 eV za čvrsto odnosno tekuće stanje. Izveli smo i temperaturnu ovisnost slobodnog volumena i našli da se linerno smanjuje s temperaturom. Ishodi mjerenja tumače se na osnovi modela slobodnog volumena
