In this investigation,differential scanning calorimetry(DSC) and metallographic experiments were performed to study α→α +β phase transformation temperature in a Zr-1.0Sn-0.3Nb-0.3Fe alloy.The deconvolution and extrapolation methods to determine the α→α+β phase transformation temperature in DSC experiment were appropriate for the Zr alloy.Moreover,precise determination of α→α+β phase transformation temperature was carried out by back-scattered electron imaging(BSEI) and electron back-scattered diffraction(EBSD) characterization techniques.The α→α+β phase transformation temperature of the Zr-1.0Sn-0.3Nb-0.3 Fe alloy was determined to be 765-770°C.