Abstract: A review of rotor/seal dynamics is given, focusing on the problems, contents, and main results achieved in modern rotor/seal dynamics. Researches of modern rotor/seal dynamics are divided into four parts: 1) modeling and calculation methods of the seal force; 2) identification of the eight lumped parameters of the seal force (the eight dynamic coefficients of the seal); 3) effect of different structure of seals (including damp-reduced structure and pre-swirl) on rotor stability; and 4) modeling and analysis of rotor/seal dynamic, especially the nonlinear dynamics of the rotor/seal model. The achieved main results are summarized as follows: 1) proposing the lumped parameter seal force model by Muszynska and Bently; 2) obtaining some techniques to identify the lumped parameters of the seal force; 3) studying some complex behaviors including bifurcation and chaos on some simple rotor/seal models; and 4) applying CFD (Computational Fluid Dynamics) to seal force calculation and rotor/seal dynamic analysis. Over one hundred of references are listed at the end of the paper. This review will be helpful for researchers of rotor/seal dynamics.