Bis-(p-bromopheny)phosphate(BBPP) , which serves as flame retardant for PET fabric, was synthesized from phenol and phosphorus oxychloride, and from bromine. In order to investigate the flame retardancy of BBPP, PET fabrics were steam-cured with diluted BBPP solution. The following conclusions were drawn : 1. Flame retardancy of PET fabrics treated with BBPP was excellent, and optimal treating condition was 10% concentration of flame retardant at $170^{circ]C$ 2. Clark softness and tensile strength before and after the laundering of PET fabrics treated with flame retardant remained nearly unchanged.