The possibility of using the magneto-optical Kerr effect in thin magnetostrictive films to study the piezoelectric characteristics of ferroelectrics is demonstrated experimentally and theoretically. A 011 PMN-PT ferroelectric crystal with an N*(TbCo 2 /FeCo) magnetostrictive nanostructure deposited on its surface is the object of study. INTRODUCTION Numerous studies of the effect deformation has on the physical properties of materials and structures have in recent years created a promising line of solid-state electronics referred to generically as straintronics[1]. Artificial multiferroics composed of elastically attached (strain-mediated) magnetostrictive and piezoelectric components are a striking example of using the straintronics concept to create materials with new properties. These materials are characterized by strong magnetoelectric coupling, which is of considerable interest for different technical applications. Magnetoelectric memory with random access (MEL-RAM) and ultralow energy consumption is one intensely studied application [2, 3]. The basis for elements of this memory is heterostructures that contain magnetostrictive films or nanoparticles with bi-or multistable magnetic systems, deposited on ferroelectric substrates. A key role in the emergence of magnetoelectric interaction in these heterostructures is played by the anisotropic piezoelectric effect in a ferroelectric, which creates deformation in a magnetic film; the symmetry of the former allows the switching of magnetization between different stable states [4]. To study the piezoelectric effect experimentally, researchers generally employ either resistive transducers, glued to the samples of interest, or ultrasonic and resonance acoustic means. These approaches are difficult to use with samples that are small or have complex topologies, which are of interest for straintronic applications. In this work, the principle of the local study of piezo-electric deformations is demonstrated using the mag neto-optic Kerr effect (MOKE) in a magnetostrictive film deposited on the surface of a ferroelectric.