The effects of ultrasound and ozone in the treatment of sewage sludge were investigated. Sewage sludge from the domestic wastewater treatment plant was partially oxdized or disintegrated by ozone and ultrasound. From the analysis of SCOD, SBOD, T-N and T-P of treated sludge, we gained as following results. In the case of ultrasonic treatment of waste sludge, the concentration of released organic materials(SCOD, SBOD) were enhanced about 3.3 times and 3.1 times respectively compared with the case of ozone treatment. And the concentration of T-N and T-P of treated sludge by ultrasound were 3.5 times much than that of ozone treatment.