The liquidus temperatures and phase relations of Ti-bearing slag systems play an important fundamental guiding role for the comprehensive utilization of Ti resources, while the lack of thermodynamic information severely restricts the development of above mentioned systems. In the present work, the phase equilibrium relationships were investigated for the CaO-SiO2-5wt%MgO-10wt%Al2O3-TiO2 phase diagram system. The equilibrium phases were experimentally determined at 1300 degrees C and 1400 degrees C using the high temperature equilibrium technique followed by X-Ray Fluoroscopy (XRF), X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM) and Energy Dispersive X-ray spectroscope (EDX) analysis. The liquid phase (L), melilite solid solution phase ((2CaO center dot MgO center dot 2SiO(2), 2CaO center dot Al2O3-SiO2)(ss)), perovskite phase (CaO center dot TiO2) and dicalcium silicate phase (2CaO center dot SiO2) were found. Based on the experimental results, the 1300 degrees C-1500 degrees C isotherms and phase relations were obtained for CaO-SiO2-5wt%MgO-10wt%Al2O3-TiO2 system relevant to Ti-bearing slag system. (C) 2016 Elsevier B.V. All rights reserved.