Human soft tissues generally exhibit complex material perperties such as nonlinearity, anisotropy, incompressibility and viscoelastictity. Soft tissue deformation is one of the most important yet difficult research tasks in virtual surgery. This paper presents a comprehensive survey on simulation of soft tissue deformation in virtual surgery. We first give an introduction of the virtual surgery system. Then we detailed various methods from geometrically-based methods to physically-based methods, from mesh-based models to meshless models. Finally, we describe some promising research directions on this topic.