Abstract: Spin-polarized scanning tunneling microscopy (SP-STM) is one of the most effective tools for the study of nanomagnetic physics as it can combine real-space atomic resolution with spin imaging. In this review we introduce the principles of SP-STM and its recent applications in the field of low-dimensional magnetic physics, such as in the analysis of magnetic films, nano-islands, atoms, and nonlinear structures. The current state-of-the-art and future developments of this field in China are also discussed.