Аннотация:The main elastic parameter of geomechanical models is the modulus of elasticity.When there is no sufficient amount of geological material (rock core), dynamic elastic moduli aredetermined using known models; the static moduli are evaluated using dynamic ones. Existingultrasonic techniques that involve generating and recording ultrasound with piezoelectriccomponents are unable to measure velocities with high accuracy. To address this problem, it isproposed to use laser ultrasonic diagnostics. In this work, we examined full-size rock samplesof different genotypes: granite and limestone. The dynamic elastic moduli of full-size graniteand limestone specimens are determined from elastic wave velocities measured with a Geoscan02MU laser ultrasonic detector operating in a through-transmission mode. The moduli of thinplate-like specimens prepared from full-size granite and limestone samples were determinedusing a UDL-2M detector operating in a pulse-echo mode. The dynamic elastic moduli of fullsize specimens and plate-like specimens were compared. Correlation and regression analysisshows that there is a close relationship between the dynamic elastic moduli of full-sizespecimens and plate-like specimens. It is found that the dynamic modulus of elasticity of rockscan be evaluated using a thin plate-like specimens prepared from undisturbed core. Also, analgorithm is developed for the preliminary assessment of the dynamic modulus of elasticity ofrocks using thin plate-like specimens.