This paper describes a computer-aid performance evaluation system for testing and checking the on-board data compression sys-tem used in High-Resolution Imaging Spectrometer(HIRIS).The earth resources spectra from the NASA earth resources spectral information system are taken for simulative spectra of ground objects and these spectra are sampled and quantized according to the conditions and parameters of HIRIS.Then the simulative spectral data are put in a GIFOV spectral data generator through a computer interface.In testing the spectral data stored in the generator are sent to the data co-mpression system at the same rate of the read out clock of subdete-ctors in HIRIS.The data compression system compresses the input data in real-time under the contral of the clock of the input data. After compressing

the compssion results are returned to computer through a bidirection interface

and compared with the original ones. Finally computer gives out testing results.This kind of test system can exactly simulate the original data obtained by HIRIS in space

and objectively evaluate the data compression system.