Guanidinium(H2N(C=NH)NH2) is also known as carbamamidine, which is formed by the substitution of the oxygen by the imino group (=NH) in the urea molecule. Because of the difference in the separation and purification of free guanidine, guanidinium is the common merchandise, such as guanidine hydrochloride , guanidine nitrate , guanidine carbonate, etc.. Guanidine is usually generated by cyanamide and excessive ammonia or ammonium chloride in ethanol and heat. It’s strongly alkaline, easy to hydrolyze and unstable under alkaline conditions. After absorption of water and CO2 from air, it will generate guanidine carbonate, which can be converted into urea after hydrolysis. It can easily generate guanidine hydrochloride, guanidine nitrate with inorganic acid such as hydrochloric acid and nitric acid, respectively. A guanidine molecule after the removal of a hydrogen atom is called guanidyl. Some drugs such as cimetidine contain guanidine structure. Guanidinium is mainly used as raw materials for the preparation of sulfonamide and muscle strain exhilarant as well as synthesis of explosives, dyes, photographic materials and disinfectants.