Abstract: Adopting tetrahydrofuran solubles of coal tar pitch (THFS) for petroleum asphalt modification, effects of different amounts of mixing, blending temperatures and cross-linking agent on the modified asphalt performance were examined. The optimum blending conditions were determined as amount of THFS, formaldehyde and trioxymethylene cross-linking agents being 8%, 0.8% and 0.2%, respectively at 135 ℃. Hexane soluble (HS) leads to the penetration and ductility of modified asphalt increase, but asphaltene (A) and preasphaltene (PA) improve the temperature sensitivity and raise the softening point. The addition of cross-linking agent improves the aging performance of modified asphalt; the methyl (CH₃) and methylene (CH₂) transmission peak intensity of modified asphalt gradually become stronger; the substituted benzene ring transmission peak intensity at 770-730 cm^-1, 710-690 cm^-1 and 770-810 cm^-1 gradually increases, and C-O-C vibration transmission peak intensity of 1 010-1 270 cm^-1 increases. The pyrolysis peak temperature moved to higher temperature, and the increase of char yield is about 2%. The modified particles exhibit a continuous distribution of flow lines, the streamline distribution of modified asphalt with adding trioxymethylene is more concentrated.