Polarization switching parameters are critically important for developing and implementing devices based on low-dimensional ferroelectric structures. Special attention is paid, in particular, to the detection of switching parameters depending on the composition and method of fabrication of the films [1], as well as to the influence of size effects and the parameters of the alternating electric field [2,3]. When passing to nanoscales, the requirements to the quality of the material are significantly increased, and the role of defects of different nature becomes decisive for the most important functional parameters of structures, such as dielectric constant, losses, switching time, etc. Fabrication of photonic crystals (PhC) based on ferroelectric thin films expands the possibilities of practical application of nanostructured ferroelectrics, but the PhCs produces additional significant inhomogeneities into the structure and functional properties of the sample. In this connection, it is necessary to study the distribution of the polarization state in the vicinity of all structural elements, as well as in the near-electrode region, depending on the parameters of applied electric field. Here we present the results of an investigation of the polarization distribution in perforated epitaxial films of barium-strontium titanate (Ba0,8Sr0,2TiO3) with the thickness of 1 µm, during the electric field application in planar geometry. The perforated structure was made by etching with a focused ion beam in the gaps between the electrodes (hole diameter 880 nm, hole spacing 1 μm). During the perforated structures fabrication, we used an equipment of the Center of Collective Use “UNO Electronika”.  The investigations were carried out by the method of electric force microscopy and piezoresponse force microscopy. A huge enhancement of effective values for both lateral and vertical piezoelectric tensors during polarization reversal was experimentally detected. This result agrees with the previously reported increase in the generation of the optical second harmonic in perforated films observed in macroscopic experiments [4]. An assumption of short range mesoscale flux-closure domain formation possibility in perforated ferroelectric structure was discussed. The obtained results are crucial for calculations of ferroelectric polarization in ferroelectric photonic crystals and metamaterials.