8/9 GMTR code is constructed and its bit error rate(BER)performance is evaluated. We assumed three types of read/write channels using a longitudinal medium, a single layered perpendicular medium and a double layered perpendicular medium. BER performance is obtained by computer simulation, and compared with those of 16/17(0.6/6)code and 16/17 MTR code. The results show that the proposed 8/9 GMTR coded E^3PR4ML system exhibits the excellent performance in all channels assumed here.