In this paper, a new three- dimensional particle beam simulation using a high performance hardware is introduced. The graphics processing unit (GPU) hardware is highly parallel and has low-cost computational capabilities. The code uses NVIDIA CUDA programming model and a particle trajectory integration steps on the graphics hardware, in a standard 4th-order Runge-Kutta scheme. The model uses mesh less representations for electromagnetic fields, based on either analytic formulas or field expansion techniques, to achieve a high degree of parallelism in the calculations. The author describe potential applications of the code for 3D simulation of vacuum electronic devices, and present details of both the algorithms used and simulation performance results.