It is formed by condensation of two urea molecules at high temperature and low ammonia partial pressure, releasing one ammonia.

White long flake crystal. No taste. It is hygroscopic. Those that crystallize in water contain 4 molecules of crystal water. It loses water at about 1 10℃, decomposes at 193℃ and becomes melamine at higher temperature. Soluble in ethanol, slightly soluble in ether.