Abstract
Using polarizing microscopy in reflected light mode, we were able to observe domain structure in the BiSrCaCuO single crystals (BSCCO) at room temperature. Formation of domains structure is a phenomenon ocurring in ferroic phase transitions. In this paper we present experimental results of optical studies of the domain structure observed in BSCCO single crystals. We observed {110} domains walls only. No phase transition was observed at high temperature when the crystal was heated up to 700°C.