<正>In 2005, the on-line ECR ion sources delivered 7 different kinds of ion beams with various energy to HIRFL accelerator. Among the 7 kinds of ion beams that the on-line ECR ion sources produced, the successive accelerator failed to accelerate Pb27+ beam (although successful before) because of its low ion beam intensity at the entrance of SFC (Sector Focusing Cyclotron). The total on-line service time of the ECR ion