Abstract: The transformation and releasing characteristics of sodium during steam gasification of the chars from rapid pyrolysis of lignite with addition of different concentrations of NaCl and NaAc have been studied in a fixed bed at 900 ℃ and 950 ℃ under atmospheric pressure. The results show that part of watersoluble sodium and acidinsoluble sodium are transformed into water insoluble but acid soluble during gasification when the concentration of sodium in char is lower. And almost all the sodium is released to gas phase when the addition of sodium is higher. The transformation characteristics of additive NaAc is different from NaCl. Nearly, all the sodium is released to gas phase during gasification. The gasification temperature and the sodium concentration show little influence on the volatility behavior.