Perlite is a silica-based organic glass. When it is instantaneously heated, it shows expansion by releasing a certain amount of water. Approximately 70% of perlite reserves in the world are found in Turkey. The porous structure of expanded perlite leads to use this material in many industrial areas; therefore, this is highly advantageous from the economic standpoint. In this study, the expansion behaviours of perlite samples, which were taken from İzmir (Bergama Mine), Kütahya (Avdan Mine), and Erzincan (Mollatepe Mine) were both characterized and investigated in the laboratory. The instrumentation techniques, X-ray Diffraction (XRD), X-ray Fluorescence (XRF), Scanning Electron Microscopy (SEM), Thermogravimetric Analysis (TGA), and Optic Microscope were used to characterize the perlite. The determination of the amorphous and crystal structure of perlite, the chemical composition of perlite, the measurement of loss of mass, the morphological characterization of perlite, and the form of raw and expanded perlite samples were obtained by XRD, XRF, TGA, SEM and Optic Microscopy, respectively. Four different heat treatments as 600 ˚C, 800 ˚C , 900 ˚C and 1000 ˚C and four different sizes 400-500 μm, 315-400 μm, 200-315 μm and 160-200 μm were conducted in the laboratory and the their bulk volumes and densities were compared before and after heat treatment. The perlite sample from Bergama 01 showed the largest expansion in all samples. As results of the analyses, the amount of crystal and water release in the perlite which had an influence on expansion process were consistent with the literature. The analyses were conducted until 1000 ˚C due to forming sinter above softening temperature. Additionally, the expanded perlite samples in the industrial furnace were compared with the expanded perlite samples in the laboratory more porous structure was observed. As a conclusion, the perlite samples from the different regions of Turkey were characterized and analyzed in terms of expansion behaviour in this study.