Abstract: Thermotropic acetylene terminated liquid crystal monomer (MPBE) was used to modify silicon-containing arylacetylene (PSA) resin to prepare PSA-MPBE resin. The structural changes of PSA-MPBE resin in the curing process were characterized by FT-IR. The pyrolysis products were analyzed by Pyrolysis-Gas Chromatograph-Mass Spectrometer (Py-GC-MS), and the curing mechanism was investigated. The phase structure, fracture morphology and microstructure of the blended resin were observed by Polarizing Microscope (POM), Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM). Results showed that MPBE could copolymerize with PSA. The mesogenic domain could be fixed in the cross-linked network to form homogeneous phase of "sea island structure". This structure changed the morphology from a typical brittle fracture to a micro plastic deformation behavior.