Hefei Light Source (HLS) has successfully finished a major upgrade project and has been officially opened to users since January 2016. The planned operation time of the year 2016 for Hefei Light Source is 7008 hours and the planned user time is 4752 hours. The actual operation time and user time is 7009 hours and 5019 hours, respectively. The machine down time is much less than the planned one, which leads to a high availability of 99.03%. The mean time between failures (MTBF) then comes to 91.26 hours. Before the upgrade project, the operation for HLS adopts current decay mode. The injected beam from the 200 MeV linac needs to be energized to 800 MeV through ring energy ramping. After the upgrade project, we now have the ability to operate Hefei Light Source in the top-off mode since the injector energy is raised to the ring energy. The main challenge for the top-off operation is to control the radiation dose for personal and equipment safety. This requirement can be met by increasing the injection efficiency and enhancing the radiation shield. This project can further increase the performance of Hefei Light Source as long as the reliability and stability of its operation.