In the last decade in Computer Graphics, they were development many techniques to simulate the behavior of objects such as rigid bodies, water, smoke, hair and cloth. While these techniques focus in simplifled physical models through monophase fluids or ideal solids, we propose new simulation techniques of viscoplastic and multiphase fluids based on a lagrangian approach of momentum equation. These techniques consist in the fluid discretization through particles system instead of traditional grid-based methods. The computational fluid dynamics is performed using the method called SPH (Smoothed Particle Hydrodynamics). In this thesis, we represent a viscoplastic material like a non-newtonian fluid that it varies between solid and liquid states, and from low to high viscosity depending on the external force applied on material or its own temperature. The simulation of multiphase fluids is made using a hybrid method grid- particle to guarantee the incompressibility of SPH method.