The PBA/P(MMA-ITA-DGEBA) latex particles were prepared by semi-continuous seed emulsion polymerization process.FI-IR was used to characterize latex with core-shell structure.Epoxy resin was toughened by latex particles with an epoxy-based core-shell.Cross section of cured resin was observed by SEM micrograph.A significant effect was significant effect in toughening of modified core-shell latex particles.Compatibility between modified core-shell latex and epoxy resin were improved.