Dynamics of polarization switching is one of the most important problem of ferroelectric-based electro-optical modulators, electro-optical switchers, and high-speed nonvolatile ferroelectric random access memories. Investigation of the dynamics of polarization reversal is highly important for optimization of the films parameters with respect to their switching characteristics. Recently it was shown [1] that nonlinear-optical microscopy based on second harmonic generation (SHG) allows to investigate both polarization switching effects and domain structure in ferroelectric and multiferroic materials. Combination of the SHG and scanning near-field optical microscopy (SNOM) techniques provides complex investigations of local ferroelectric properties for nanosized thin films and planar structures with high spatial resolution up to 100 nm. In this paper we report the results of polarization switching in Ba0,8Sr0,2TiO3/Bi0.97FeNd0.03O3 (BST/NBFO) planar structures studied by combination of the SHG and SNOM techniques. Heteroepitaxial multilayer BST/NBFO structures with various thickness of the single layer (d1 = 3nm, d2 = 6nm) were fabricated by high-frequency sputtering on MgO(100) substrate. Chemiclal compositions of the BST and NBFO layers allows to perform all measurements at the room temperature. Epitaxial structure of the films was confirmed by X-ray diffraction. Aluminum planar electrode system with the gap of 20 μm was deposited on the film surface by vacuum deposition for electric field application, which provides in-plane switching of the ferroelectric polarization during voltage application up to ±50 V. Voltage dependencies of the SHG intensity were investigated for different thickness of the layer as well as spatial distribution of ferroelectric properties in the gap between two planar electrodes during DC voltage application by pattern 0 – Umax – 0 – (-Umax) – 0. This work is supported partly by Russian Founadion of Basic Research and Russian Ministry of Science and Education. [1] E.D. Mishina, S.V. Semin, K.V. Shvyrkov, A.V. Kudryavtsev, N.A. Ilyin, N.E. Sherstyuk, V.M. Muhortov. Physics of the Solid State, v. 54, i. 5, p. 836 (2012).