Abstract: Tri(3-acetylenephenylamino)phenylsilane (SZTA) was synthesized by aminolysis reaction using phenyl trichlorosilane and 3-aminophenylacetylene as raw materials. The structure of SZTA was characterized by Fourier Transform Infrared spectroscopy (FT-IR) and proton Nuclear Magnetic Resonance spectroscopy (¹H-NMR). The modified resins (PSA/SZTA) were prepared by melt blending silicon-containing arylacetylene (PSA) resin and SZTA in different ratios. The properties of the modified resins such as the process property, curing reaction, flexural property, thermal stability, and the pyrolysis dynamics were investigated by viscometer, rheometer, Differential Scanning Calorimetry (DSC), electronic universal testing machine, and Thermogravimetric analysis (TG). The results show that the viscosity of the modified PSA resin decreases by 62% after introducing SZTA. The flexural strength of the cured PSA/SZTA is up to 34.6 MPa, higher than that of PSA by 54%. The modified PSA resins maintain good heat resistance as the degradation temperatures at 5% mass loss (T_d5) in N₂ is above 500℃. The average degradation apparent activation energy (E_a) of the cured PSA/SZTA-20 is 249 kJ/mol based on Ozawa method.