Phase Change Random Access Memory (PCRAM) has already been shipped into the market as new non-volatile memory. All PCRAM usually use a Ge-Sb-Te chalcogenide thin film, which enables to switch electric resistance high (MΩ) or low (kΩ), depending on the phase: amorphous or crystal. To make an amorphous phase, it once needs to heat up the cell temperature higher than the melting point (900K) by injecting a large current pulse to PCRAM. This process has been a big issue to consume a relatively large electric power in PCRAM. Recently, a new PCRAM named interfacial phase change memory (iPCM) has intensively been studied because iPCM no longer require “amorphous phase” in switching. In the short course, the background and basic mechanism of the current PCRAM is introduced first, and then the detail mechanism and the performance of iPCM are explained. In addition, we discuss the application for spintronics by iPCM.