At present Nd2Fe14B is the best permanent magnet because of its extremely high coercivity and energy product. Optimum properties of Nd2Fe14B magnets can be attained by producing single domain particles, and then aligning and compacting them. Due to the high reactivity of the Nd constituent, it is challenging to produce and handle a large amount of fine particles of this material. We have prepared fine particles of Nd2Fe14B by spark erosion with various dielectric media. Yield, size, size distribution, structure, and magnetic properties are discussed. The Nd2Fe14B particles were made by the shaker pot spark erosion method. Relaxation oscillators or a pulse generator were used to power the spark erosion. Commercial Neomax 35 was employed as the primary material. The dielectric media were liquid Ar, Ar gas, and hydrocarbons, which provided an oxygen free environment. Structure and size were studied by TEM, SEM, and x-ray diffraction. Magnetic properties were measured by VSM with temperatures in the range of 4.2–1200 K. The particles produced in these three different dielectric media had different microstructures and crystal structures. The particles made in Ar gas were pure Nd2Fe14B phase. The particles made in liquid Ar were a mixture of amorphous and crystalline Nd2Fe14B, because the liquid Ar provided a much higher quench rate than Ar gas, which produced some amorphous Nd2Fe14B. Upon annealing, the amorphous particles became crystalline. The fine particles produced in hydrocarbons, such as pentane and dodecane, had more complex mixed phases, since the rare earth reacted with the hydrocarbons during the sparking process. The phases were NdC2, α-Fe, and amorphous and crystalline Nd2Fe14B. The effects of power parameters, such as voltage and capacitance, on particle size were investigated. Particle sizes from 20 nm to 50 μm were obtained. We concentrated on Nd2Fe14B fine particles made in liquid Ar and Ar gas. Particles were classified by centrifuging and sizes were confirmed by TEM and x-ray diffraction. The size dependence of coercivity, anisotropy, and magnetization of these Nd2Fe14B particles will be discussed.