A method for estimation of elastic wave velocity anisotropy based on ultrasonic sounding data during rock-sample loading was developed. The subject matter of the method is approximation of ultrasonic sounding data by triaxial velocity ellipsoid. The applicability of proposed method was verified on investigation of anisot ropic rock samples. Laboratory loading of migmatite samples was realized under various mutual orientations between acting force direction and rock foliation - perpendicular, parallel and under 45°. P-ve velocity of ultrasound waves was monitored by 8 sensors network. The velocity ellipsoid was computed and changes of sizes and waorientation its main axes during loading were analyzed for separate experiments with regard to loading level. It was found, that independently to mutual orientation between rock foliation and loading direction, the minimum velocity vector turns to perpendicular direction to final rupture plane and maximum velocity vector turns to the plane of final rupture., Matěj Petružálek, Jan Vilhelm, Tomáš Lokajíček and Vladimír Rudajev., and Obsahuje bibliografické odkazy