Abstract: In recent years, the computer has been widely used in ESR spectroscopy. A new ESR data system had been developed which can carry out acquisition, processing and simulation of measured data.This sytemconsists of a floppy disk, an interface, a keyboard, a plotter and a graphic display terminal, and is based on a general IBM PC microcomputer. The interface includes a 12 bit DAC to control the magnetic field and to output data to a X-Y recorder and 12bit ADC which can be used to a digital acquisition of ESR spectra. This software has the following three functions:Data acquisition, data processing and spectrum simulation. Data processing composed of several modes:accumulation and average, smoothing, integration, subtraction, gvalue, calculation.This system had been used for analysis and simulation. The advantage of this system is low cost and easy operation.

Key words: ESR data system, IBM PC computer, Software system, Sardw are syste, Hardware system