The vitro blood anticoagulant activities,including rothrombin time (PT),plasma recalcification time (RT) and kinetic cloting time,were measured and compared for pure magnesium,magnesium alloys and a comparison material (316L stainless steel). The pure magnesium rods were implanted into the back muscle of rats to evaluate the osteo-induction.The results showed that the blood anticoagulant activities were in the order of Mg