In recent years, the demand of renewable energy fuels has been increased in worldwide because the capacity of fossil fuel would be not affordable in the near decade. As one of renewable energy fuels, the production of sewage sludge would be gradually increased by year, and it would be over than 10million tons in 2015 in Korea. Since ocean dumping was inhibited due to London Convention with being in effective at the end of 2012 in Korea, the combustion of sewage sludge has been emerged as one of alternative technologies of waste to energy. Meanwhile, it would be necessary to apply the carbon capture & storage (CCS) technology to reduce carbon dioxide originated from waste sludge incineration. During oxy-fuel combustion, a combination of oxygen typically of greater than 95% purity and recycled flue gas is used for combustion of the fuel. By recycling the flue gas, a gas consisting mainly of CO₂ and water is generated, ready for sequestration without stripping of the CO₂ from the flue gas. In this study, the pilot test was conducted by a circulating fluidized bed (CFB) combustor consisting of a riser, a cyclone, a down-comer, and a loop-seal. The CFB combustor has a riser with an inner diameter of 0.15m and a height of 6.4m. The experimental test was carried out with waste sludge in 30kwth CFB combustor operating with oxy-fuel and typical air conditions. The optimum temperature for waste sludge incineration was determined as 800℃. Oxygen with carbon dioxide as a combustion air was fed into a riser and a loop-seal in pilot test bed. The oxygen rate as a combustion air was ranged from 21% to 30% to observe the condition of waste sludge oxy-fuel combustion. The temperature and pressure profile in CFB reactor were depicted in the condition of typical air and oxy-fuel combustion. The flue-gas from typical air and oxy-fuel combustion was analyzed to observe the trend of carbon dioxide and air pollutants emission such as CO, NOx, and SOx, respectively. The production of carbon dioxide was approximately 90% in flue-gas from waste sludge incineration with oxy-fuel condition.