A series of transparent ABS(T-ABS)resins have been prepared by emulsion in situ suspension polymerization process It was found that the transparence of T-ABS was satisfactory but the impact strength was lower when smaller SBR particles was used as rubber phase．The transparence of T-ABS was lowered when larger SBR particles were used as rubber phase．When SBR bi—modal particles(S70 nm／S400 nm=4／6～6／4

total rubber content 15％ to 18％)were used as the dispersion phase

the transparence of ABS resin was higher then 80％and the impact strength was between 90 J／m and 120 J／m．The brittle-toush transition of T-ABS resin using different SBR particles as rubber phase was preliminarily discussed．Synergistic toughening effect of different SBR particles on T-ABS resin was studied．The basic conditions under which the prepared T—ABS resin showed high transparence and satisfactory mechanical properties were found．