Objective：To overcome the drawbacks of traditional nanomedicines with a poor stability，a short blood circulation，and a high immunogenicity，a novel zwitterionic nano-vector with sterling stability and non-specific protein resistance were designed and prepared. Methods：A biodegradable carboxybetaine（CB）-modified polycarbonate［PAC（TCB）］was designed and synthesized by ring-opening polymerization and Michael addition reaction，which can form the micelles of around 160 nm via a solvent displacement method. Results：Cellular uptake and cytotoxicity experiments demonstrated that PAC（TCB）micelles possessed the superior characteristics of an efficient cell internalization，and an excellent biocompatibility. The hemolysis assay and in vivo pharmacokinetic experiments confirmed that PAC（TCB）micelles led to a low immunogenicity，a prolonged blood circulation and a negligible antibody effect after repeated injections. Conclusion：The biodegradable zwitterionic-functionalized polycarbonate displays a colossal potential as the nano-vector in drug delivery.