Rheological　properties　and　the　impregnating　performance　of　three　pitches,　including　terephthalic　aldehyde-modified　pitch,　and　optical　textures　of　resultant　carbon-carbon　composites,　were　studied.　The　results　showed　that　the　impregnating　performance　of　pitch　became　good,　and　anisotropic　unit　size　of　the　optical　textures　got　large　with　improvement　of　rheological　properties　and　decrease　of　quinoline　insoluble　(QI)　content.　Moreover,　the　impregnating　efficiency　of　the　modified　pitch,　indicated　by　densification　degree　of　carbon-carbon　composites,　was　much　higher　than　those　of　the　unmodified　pitches　during　first　two　impregnation/carbonization　cycles.