Operating license extension (OLE) is an important trend in the development of Nuclear Power Plants (NPPs). About 30.2% of the units in operation in the world have reached or exceeded 40 years of operation. “License Renewal, LR” and “Periodic Safety Review, PSR” are two commonly strategies used for operating license extension demonstration. In December 2015 the technical policy of OLE in China was issued by National Nuclear Safety Administration (NNSA), with the main works of the demonstration include: (1) Current License Basis Review, (2) Scoping and Screening of Structures, Systems and Components (SSCs), (3) Aging Management Review (AMR), (4) Time Limited Aging Analysis (TLAA), (5) Updated of Finally Safety Analysis Report (FSAR), (6) Environment Evaluation. The demonstration of OLE of NPPs were carried out in two NPPs since 2013. In this paper, the demonstration strategies for OLE were introduced, the processes of the demonstration by LR in USA and PSR in France were provided. The interpretation of technical policy and Domestic status of OLE in China were illustrated. The technical issues for the OLE safety assessment were also reviewed. Furthermore, the trends for OLE in the future, such as multiple plants demonstration at one time, the secondly license renewal were discussed as well.