Ambient noise seismic interferometry is the methodology by which the Green's Function between two seismic stations can be extracted from long time cross correlation of ambient noise recorded by these two stations． Recent years，seismic interferometry based on ambient noise gains lots of advances both in theoretical derivations and practical applications，including ambient noise tomography as well as time lapse monitoring of velocity variations and many others． In this paper，we first give a brief introduction to the concept and theory of seismic interferometry，then put more words on the new advances in its applications． After introduction and discussion on the advances and barriers related to research on ambient noise source properties，phase and amplitude of noise cross correlation function，we show the new trend in ambient noise interferometry processing．