Title: Diffusion-based point cloud generation with smoothness constraints. Abstract: Diffusion models have been popular for point cloud generation tasks. Existing works utilize the forward diffusion process as a discrete Markov Chain to convert the original point distribution into a noise distribution (e.g., standard Gaussian distribution)  and learn the reverse diffusion process to recover the target point distribution from the noise distribution. However, the diffusion process can produce samples with non-uniform points on the surface without consideration of the point cloud geometric feature. To alleviate the problem, we propose a novel diffusion-based framework for point cloud generation and incorporate the local smoothness constraint into the generation process. Experiments demonstrate that the proposed model is not only capable of generating realistic shapes but also generating more uniform point clouds, outperforming multiple state-of-the-art methods. 