The present research aims at developing a new quantitative thermal analysis method based on differential scanning calorimeter for determination of cristobalite phase content in ceramic cores. For this purpose, various control samples with different amounts of cristobalite phase were made based on the chemical composition of silica-based ceramic cores and analyzed via differential scanning calorimetry (DSC) technique. The surface area under the α → β cristobalite transition peak in the DSC curves was calculated via numerical integral of the peaks area, and the ratio of this area to the samples weight (A/W) was calibrated by cristobalite content of the samples. Afterward, for determining the cristobalite content of some industrial samples, the DSC patterns were plotted, and the A/W ratio of these samples was determined by the same method. Then the A/W ratios of the industrial samples were fitted on the calibration line, and the cristobalite content was derived using the equation of the calibration line. The method showed good accuracy, and the error values of the estimated cristobalite content of the industrial samples were below 2 %.