Livestock wastewater is generally very difficult to be treated by conventional wastewater treatment techniques because it contains high strength of organics (COD), ammonia nitrogen (NH4+ -N), phosphate phosphorus (NH4+ -N) and suspended solids. In this study, struvite crystallization was carried out to treat livestock wastewater. 1.0:1.2:1.2 was determined as an optimal NH4+ :Mg^(2+) :PO4^(3-) mol ratio of struvite crystallization for raw livestock wastewater as well as digested livestock wastewater. The struvite crystallization efficiencies of digested livestock wastewater was higher than those of raw livestock wastewater. For the digested livestock wastewater, COD, NH4+ -N and PO4^(3-) -P removal efficiency by struvite crystallization was 72.4%, 98,9%, and 75.4%, respectively.