Some of the recombinant protein therapeutics with short half-life requires high frequent dose or injection, which results in poor patient compliance. This challenge has prompted the development of long-acting recombinant proteins in recent years. Four strategies and methods, including chemical modification, protein engineering, fusion proteins and protein glycosylation are used to modify protein molecule and finally obtain improved pharmacokinetics (PK) properties. This article reviews the four strategies of half-life extension and presents a detailed list of long-acting therapeutics on US, EU and China markets.