In the present study, SBA-15 molecular sieve was successfully synthesized by a microwave-assisted hydrothermal synthesis method, using poly(ethylene glycol)-block-poly(propyl glycol)-block-poly(ethylene glycol) (EG(20)PG(40)EG(20)) as a template. The time of synthesis of SBA-15 molecular sieve by microwave-assisted hydrothermal synthesis method only needs 125 min, synthetical speed is 34 times faster than that by the conventional hydrothermal synthesis method. The results showed that the primary particles of the samples present acicular crystals. The longness is 100 mu m for SBA-15 sample synthesized by microwave method in 5 min (S-1) and 64 pm for SBA-15 sample synthesized by microwave method in 0.5 h (S-2), respectively. The diameters are 4.5 mu m for S, sample and 3.6 mu m for S-2, sample, respectively. These data showed that the sizes of the SBA-15 molecular sieve synthesized by present method were much bigger than those by the conventional hydrothermal synthesis method and by the other microwave-assisted hydrothermal synthesis methods.