A stable and efficient Pd(OAc) 2 /PPh 3 /PEG-2000 catalytic system for homocoupling of arylboronic acids has been developed. In the presence of Pd(OAc) 2 and PPh 3 , the homocoupling reaction of arylboronic acids was carried out smoothly in PEG-2000 at 70°C under air without base to afford a variety of symmetric biaryls in good to excellent yields. The isolation of the products was readily performed by extraction with diethyl ether, and the Pd(OAc) 2 /PPh 3 /PEG-2000 system could be easily recycled and reused six times without significant loss of catalytic activity.