Abstract: Nitrogen and phosphorus in wastewater are a burning environmental issue of the present world，and they can be removed or recovered through struvite crystallization.The principles and influencing factors of struvite′s nucleation and crystal growth were introduced.The influences of different factors，such as various Mg sources，supersaturation，amount-of-substance ratio of Mg2+，NH4+，PO43-，pH，impurity ion，reaction time，and temperature，on the P and N removal efficiencies and struvite crystallization were also discussed.Struvite contains nitrogen，phosphorus，and magnesium，and the slower nutrient leaching loss makes it a slow-release eco-friendly fertilizer.It is possible to overcome the acute shortage of rock phosphate if all the phosphorus in municipal and livestock wastewaters is recovered by wastewater treatment plants，realizing the recycling of phosphorus.

Key words: struvite, slow-release eco-friendly fertilizers, wastewaters, crystallization