报告摘要： Spin-transfer torque (STT), induced by spin-polarized current, can induce magnetization reversal or excite a steady precession of the magnetization in a nanomagnet. This brings some promising new technologies such as STT-based memory and microwave oscillators. The total addressable market in STT- memory will be > $80 by 2015.  However, there are many challenges  before they come to commerce. In this presentation, at first we will review  the history and present development of STT nanodevices, and then present our recent progress in STT study.