Since processors are shifting towards parallel architecture at the present time, it is impor-tant to develop data-parallel algorithms to exploit their computational power. This paper presents a parallelized real-time particle-based simulation method. Particle-based simulation is accelerated by using Graphics Processing Units (GPUs) as a parallel computation platform. With parallelized particle-based simulation, the number of particles which can be simulated in real-time is increased by more than an order of magnitude. This paper also presents a particle-based method to interact fluids and rigid bodies. Rigid bodies are represented by a set of particles. The benefits of this method are not only low computational cost but also parallelism of its algorithm. By simulating fluids, rigid bodies and their interactions in real-time, we demonstrate the capability of the parallelized particle-based simulation. icle-based simulation is accelerated by using Graphics Processing Units (GPUs) as a paral-lel computation platform. Parallelized particle-based simulation enables us to use several tens of times more particles as used before in real-time. By simulating fluids, rigid bodies and their interactions in real-time, we demonstrate the capability of the proposed method.