Abstract: This paper deals with the toughening bismaleimide (BMI) resin with thermoplastic (TP) resin,Polysulfone an d Polyether sulfone.The experiment shows that the viscosity of toughened resira is 0.5(Pa·S)at 150℃, the forming pressure of their composites is between 0.3-0.7 (MPa),curing temperature is 180℃,all of the properties mentioned above can meet the technological requirement of autoclave forming. The prepregs impregnated with these resins have quite good tack and drape,the shelf-live is more than one month(at room, temperature).The toughened resins keep quite good heat resistence and can be used permanently at 177℃.The impact strength of their composites increases obviously and, being toughened with PSF,by a factor of 90%.The toughening effect of PSF is better than that of PES.