Abstract: In order to investigate the interlayer toughening effect on damage resistance and damage tolerance , carbon fiber/ bismaleimide resin laminates HT3/ Q Y8911 were interlayer toughened with thermoplastic particles. Thequasi-static indentation (QSI) test and compression test af ter impact were conducted to determine the damage resistance and damage tolerance of non-interleaved and interleaved specimens. Visual observation and ult ra-sonic C scanwere also employed to inspect the damage size. The delamination onset load for 2 mm thickness interleaved specimens is remarkably increased , while the delamination onset load2drop magnitude for 4 mm thickness interleaved onesis significantly decreased. These two parameters can be used to characterize damage resistance under quasi-staticforce. Under the same load or same impact energy per unit thickness , interleaved specimens have a smaller damagearea at the expense of relative deeper indentation in the local region. In the case of similar damage size , the compression st rength af ter impact and the ultimate failure st rain of interleaved HT3/ Q Y8911 are obviously improved , andtherefore higher damage tolerance is achieved.