It can be concluded from the results shown in Figs. 4–6 that the leached heavy metals of stabilized flyash (such as Pb, Cd, Zn and Cr) can be reduced by over 85% using heavy metal chelating agent at a chemical dosage of 0.2% by weight, and the reduction rate of the leached heavy metals can be higher than 90% at a chemical dosage of 0.4 and 0.6% using the chelating agents. For a comparison, the leached heavy metals of stabilized flyash using inorganic agents for sodium sulfide and lime were much higher (see Table 3),and the reduction rate of the leached heavy metals was much lower than 80% even if the chemical dosage was reached 0.6% by weight.