In this research, 4-stage intermittently aerated activated sludge system was investigated for simultaneous nitrogen and phosphorus removal with swine wastewater. COD_(Cr), TKN and Po₄³-P concentration of swine wastewater were 3151, 192 and 25.2㎎/L, respectively. Operational conditions were SRT 20day, HRT 24hr and aeration/ nonaeration time lhr/lhr, respectively. Organic matter in influent was devided into total, filterable, readily biodegradable and soluble inert organic. Portion of particulate, readily biodegradable and soluble inert organic to the influent organic were 65.6, 24.4 and 5.4%. The effluent TSS and COD concentrations has been consitently below 30㎎/L and 200㎎/L. In first reactor, release-uptake of PO₄³-P was observed very well but in third and fourth reactor, PO₄³-P concentration showed almost no change at below 0.1㎎/L. Nitrification and denitrification were observed to progress almost completely. COD_(Cr), T-N and PO₄³-P removal efficiency were 93.8, 88,6 and 95%, respectively.