粉体粒度及粒度分布是粉体颗粒最重要的特性。以稀土永磁材料NdFeN为例，采用激光散射法(干法和湿法)和扫描电镜法对其粒度进行了分析，并比较了三种方法的测试结果。测试结果显示，粒度分析时样品的充分分散是准确测量的基础。将显微镜的直观与激光粒度仪的快速、准确和方便结合起来，对于保证粒度分析结果的可靠性非常有用。

Particle size and Particle size distrubition is the most important character of powders. We test rare earth permanent material NdFeN, particle size is analysed by laser light scattering method (dry method and wet method) and SEM, then the three test results are compared. The test results show, when the particle size is analyzed the abundant scattering of the sample is a foundation measured accurately. Combine the intuition of microscope and fast, accurately, conveniently of laser size instrument, for guaranteeing the reliability of the particle size analysis result is very useful.