the ultrasonic extraction method of tetrabromobisphenol-a (TBBPA) in polystyrene was studied.The parameters for studied such as,weight of sample,type of organic solvent, volume of organic solvent,extraction temperature and extraction time were carried out in order to increase the exatraction efficiency. In extraction process, the PS sample of 0.5 g was used .The optimum solvent was 15 mL of isopropanol . The extraction temperature and exatraction time were 65 c and 60 min respectively . The linearity was0.001-0,006 % (w/w) with R2=0.9946 . The limit of detection (LOD)and the limit of quantification (LOQ)were 0.001 and 0.003% (w/w),respectively . the %RSD and %recovery were less than 1% and 89-107%,respectively. The extraction efficiency of this method was more than 89%.