Livestock wastewater generally contains high strength of organics (COD), ammonia nitrogen (NH4+ -N), phosphate phosphorus (NH4+ -N) and suspended solids. It is very difficult to treat by conventional wastewater treatment techniques. In this study, gamma ray irradiation was carried out prior to struvite crystallization of livestock wastewater. The enhancement of struvite crystallization efficiency could be obtained by gamma ray irradiation pretreatment due to the decrease of COD, NH4+ -N and PO4^(3-) -P concentration.