Sulfuric acid-modified polyethylene glycol 6000 (PEG-OSO3H) was applied as an efficient and recyclable catalyst for the synthesis of β-amino carbonyl compounds via the Mannich reaction between aldehydes,aromatic ketones and aromatic amines at room temperature using PEG400-H2O (1∶1) as environment-friendly solvents.The reactions were completed in short times and mild reaction conditions with good to excellent yields.