The solution of thermal stability of stabilized chlorine dioxide and acidity influence on activation effects are studied, and is contrasted with solution of chlorite. The inactivation effect on bacteria and HBsAg are researched after stabilized chlorine dioxide are activated. The results show that the aqueous solution of stabilized chlorine dioxide is different from NaClO₂ aqueous solution and its thermal stability is better than NaClO₂. The activation effect of hydrochloric acid is better than that of citric acid.