The eutectic and peritectic melting equilibria of the Sr 14Cu 24O 41 phase have been studied at oxygen pressures of 0.0075, 0.021, and 0.1 MPa. The Sr 14Cu 24O 41 primary phase field was determined using a combination of differential thermal analysis and electron beam microanalysis of quenched liquids. It was found that the incongruent melting of Sr 14Cu 24O 41 takes place at 925, 975, and 1032°C at P O 2 =0.0075, 0.021, and 0.1 MPa, respectively. The peritectic melting reaction under all conditions was confirmed to be: Sr 14Cu 24O 41→SrCuO 2+Liquid+O 2. The liquid composition of this melt was found to range from 79.8% (mole fraction, at P O 2 =0.0075 MPa) to 83.9% CuO (mole fraction, at P O 2 =0.1 MPa). The copper oxidation state in these liquids, as estimated from thermogravimetric data, ranged from Cu +1.42 (at P O 2 =0.0075 MPa) to Cu +1.46 (at P O 2 =0.1 MPa). The eutectic melting in the SrO–CuO system occurs at 918°C (mole fraction of 81.7% CuO), 965°C (mole fraction of 85.0% CuO), and 1005°C (mole fraction of 86.7% CuO) at P O 2 =0.0075, 0.021, and 0.1 MPa, respectively. The temperature range of the Sr 14Cu 24O 41 primary crystallization field was found to increase from 7°C at P O 2 =0.0075 MPa to 28°C at P O 2 =0.1 MPa, but the compositional width remains small (<4%) at all three oxygen pressures. These data provide important points on the Sr–Cu–O phase diagram. The data are discussed with reference to the growth of Sr 14Cu 24O 41 crystals.