Enoxaparin sodium is a low molecular weight heparin sodium derived from heparin sodium extracted from pig intestine mucosa. It is a benzylidene sodium derivative of heparin obtained by esterification. Structurally, it is composed of many complex and undefined oligosaccharides. Most oligosaccharides have 4-enol pyranose acid at the non-reducing end of the sugar chain, and 1, 6-dehydrated structure at the reducing end of the sugar chain, accounting for 15-25% of all sugars.

　　The weight average molecular weight of enoxaparin sodium ranged from 3800 to 5000, the weight weight percentage of oligosaccharides with molecular weight <2000 ranged from 12 to 20%, and the weight percentage of oligosaccharides with molecular weight 2000 to 8000 ranged from 68 to 82%. The titer of enoxaparin sodium against factor Xa ranged from 90 to 125IU per mg of dry substance. The ratio of anti-XA to anti-IIA ranged from 3.3 to 5.3.

　　Enoxaparin sodium catalyzed the inactivation of clotting factors IIa, Xa, IXa, XIa and XIIa by binding with antithrombin III(AT-III). Among them, the anticoagulant effect was mainly exerted by inhibiting Xa.