This thesis that implemented Monte Carlo path tracing and voxel cone tracing for global illumination on GPU compared the performance and visual result. The Monte Carlo path tracing algorithm is implemented in CUDA to do parallel computing on GPU and accelerate the computing speed. The voxel cone tracing, a global illumination algorithm for real-time computing, runs on OpenGL through the GPU graphics pipeline. The results show that the Monte Carlo Path Tracing on CPU single core takes over 10 hours, around 4 hours with 4 cores, on GPU it takes around 48 minutes, while the voxel cone tracing on the same GPU takes 2 ms. The quality of the image generated by the Monte Carlo path tracing contains much more transparent, reflection, and shadow details than that using the voxel cone tracing algorithm. / <p>Examensarbetet är utfört vid Institutionen för teknik och naturvetenskap (ITN) vid Tekniska fakulteten, Linköpings universitet</p>