The　thermotropic　liquid　crystalline　copolyamide　(TLCPa)　was　synthesized　and　the　in　situ　composites　for　TLCPa/Polyamides　66　(PA66)　were　prepared　by　melting　extrusion.　As　revealed　by　differential　scanning　calorimeter　(DSC),　depression　of　the　melting　point　and　the　crystallinity　of　PA66　indicated　that　the　miscibility　was　enhanced　via　intermolecular　H-bonds.　Characteristic　absorption　shifts　of　C=O　groups　of　TLCPa/PA66　in　Fourier　transform　infra-red　spectra　(FTIR)　confirmed　the　existence　of　H-bonds.　Scanning　electron　microscope　(SEM)　observation　showed　that　the　shape　of　TLCPa　phase　change　in　matrix　with　increasing　TLCPa　content.　Mechanical　properties　of　blends　were　significantly　improved　by　good　interface　adhesion　and　TLCPa　fibrils　generation.