Novation of obligation not only conform to the principle of freedom of contract and modern efficiency, but also has great significance in consummating the following institution of civil law: transfer of obligation, guaranty of debt, prescription and termination of obligation. 债的更新不仅符合合同自由和现代效率原则,而且对于债之移转、债的担保、时效以及债的消灭等制度的完善均有重要意义。