In order to develop a recycling process of magnesium scraps, a fundamental study on the evaporation behavior of magnesium melt was carried out. Melt temperature, vacuum degree, surface area of melt, and reaction time were considered as experimental variables. The evaporation amount of magnesium increases with the increase of reaction time, melt temperature, surface area of melt, and vacuum degree. In the pressure range below 6650 Pa, the evaporation rate of magnesium sharply increased with the increase of the vacuum degree in the reactor. When the pressure increased over 6650 Pa, the evaporation rate of magnesium was very low and independent of the pressure. An empirical equation for the evaporation rate of magnesium melt was derived. The evaporation coefficient of magnesium was determined to be about 9.074 x 10(-5) under investigated conditions.