The chemical states of Cu, Zn, and As in sewage sludge have been investigated by X-ray absorption. ne structure (XAFS) spectroscopy. XAFS spectra show that Cu and Zn of 150ppm - 200ppm form sulfides of 2+, and As of less than 250 ppb exists as 3+ in the sludge under anaerobic state. The in-situ XAFS measurements reveal that under aerobic states, Zn sulfide is partially dissolved and As is partially oxidized to 5+ although Cu maintains sulfide form. The stability of these compounds in the sewage sludge is discussed.