Since CIAE- HI13 tandem accelerator was accepted in 1987

the accelerator has been in operation for more than four years. In this period

the beam time on the targets of this machine has accumulated for 13000 hours. In this paper the work status of the machine in the last four years has been mentioned. The accelerator was conditioning as high as 13.4 MV terminal voltage with the highest voltage for experiments at 12.6 MV and the lowest voltage at 2.08 MV More than 20 of various ion species were accelerated through the tandem machine. The people who worked in the field of the operation and maintenance of the tandem have accumulated some important experience

such as the assembly

installation and adjustment of the Laddertron chain

the high voltage conditioning

the government of the stabilization system and the control system. Some troubles encountered in the last four years have been smoothed over. Up to now

the machine is quite satisfactory.