A series of hydroxy-terminated polybutadiene (HTPB) polyureas modified with different liquid polysulfide content was synthesized and their structure and oil-resistant properties were studied by attenuated total reflectance-FTIR spectroscopy, dynamic mechanical analysis, isothermal aging and differential scanning calorimetry, stress-strain analysis, oil absorption, and oil-resistance test. The results showed that polysulfide-polybutadiene polyureas retained low temperature flexibility and had lower oil absorption and better oil resistance than that of HTPB-based polyureas. (C) 2003 Wiley Periodicals, Inc.