Antibody drug is a kind of glycoprotein which molecular weight is over one hundred thousand. The number of pharmaceutical approval of antibody drug has been increasing in recent years. In terms of a working mechanism and pharmacokinetics, antibody drug is markedly different from existing low molecular weight drugs. In prospect, about body kinetics is the same. This paper describes general features of antibody drug mainly about internal kinetics in the first half. In the last half, body kinetics of human anti-RANKL monoclonal antibody called Denosumab and body kinetics changes in special population are outlined.