The influence of the addition of boron on weight variation of silicon melt due to evaporation was investigated. It was found that the evaporation loss of the 1021 atoms/cm3 boron-doped silicon melt was larger than that of non-doped silicon melt. In particular, it appeared that boron enhanced the weight variation of the silicon melt at high temperature (1550° C) by assisting the evaporation from the melt. Deposits collected by a well designed collector were analyzed by electron probe microanalysis (EPMA) in order to identify the chemical species evaporated from the boron-doped silicon melt. It was found that the predominantly evaporated species from the boron-doped silicon melt was silicon oxide. It could be concluded that the addition of boron into the silicon melt enhances the evaporation of silicon-oxide.