Abstract: The temperature field of FGH95 alloy droplet atomized by plasma rotating electrode processing (PREP) during solidification has been calculated through numerical analysis based on equivalent sensible heat capacity method. And thus the relational culves among temperature gradient of solid-liquid interface, moving velocity of solid-liquid interface and solid fraction during solidification have been presented. The results indicate that the relation between average temperature gradient of solid-liquid interface and droplet size, and the relation between average moving velocity of solid-liquid interface and droplet size can be expressed during solidification.