Abstract: The high temperature, aerobic and forced aeration static-composting system wereadopted to study the changes in total contents of heavy metals, including Cu, Pb, Zn, Cd and As, as well as their status contents of unstable states (includingexchangeable state, carbonate combination state and Fe-Mn oxide combination state) and stable states (including organic combination state and residuum state) during different proportion mixed of sewage sludge and sawdust, fly ash or phosphate rocks composting process. Then the passivation effect of fly ash and phosphate rocks in the compost process was discussed. The results show that this process may remarkably reduce the content of sludge exchangeable Cu, Pb, Zn, Cd, As and increase the content of others, but cannot reduce the heavy metals over all contents. To reduce crops available state and increase the content of other states of heavy metals, it is discovered that test A is best, B and D are secondary, and test C is final. Meanwhile, fly ash and phosphate rocks are found to be goodpassivators; their usages are necessarily as many as possible for the passivation effect. In these tests, the usages of them were about 15%, and the passivation effect of fly ash was superior to that of phosphate rocks.