Monodispersed bismaleimide resin microspheres with diameter of 3／μm were prepared by chemically induced phase separation in polyetherimide and bimaleimide resin blends．The morphology of bismaleimide resin microspheres was investigated by SEM

and BMI resin micmsphere particle sizes and their distribution were characterized by LPS．The resuhs showed that the morphology of bismaleimide resin microspheres has evident relations with the structure of the used polyethefimide and polyesterimide．With increase of polyetherimide content

the microsphere size decreased．but the size distribution variation showed a wide-narrow-wide process．The DSC measurements showed that Tgof bismaleimide resin microsvheres was 215～218℃ slightly lower than that of the neat bismaleimide resin.