Abstract: In magneto optical (M-O) storage system,the read/write characteristics of the recording media,(M-O) material film,has direct effects on the performance of M-O storage system,such as SNR,quality of readout signals,direct erase/rewrite processing,etc.As a result,developing new M-O materials with good read/write characteristics could improve the performance of M-O storage system.In this paper,a system for testing read/write characteristics of M-O materials is presented.Static read/write tests have been applied to the new M-O materials,MnBiAl,which has large Kerr rotation.The experimental results give useful data for the improvement of read/write characteristics and the study of the practicality of this new M-O materials.