As a new class of stimulus-responsive surfactants, a series of alpha-methyl-omega-alkyl PEGs endowed with a carboxylic acid moiety at the hydrophobic terminal was Successfully synthesized with 56-97% yields. They were characterized by IR, NMR spectroscopic and MALDT-TOF MS analyses. It is suggested by DLS measurement that the collapse of the micelle-like aggregation occurred under basic condition. This synthetic procedure would be applicable to surfactants with sufficient hydrophilic and lipophilic balances, allowing precise control of pH-responsive micellar systems.