A new synchronous fluorescence scan analysis was developed for the determination of HSA with high sensitivity with a triphenylmethane acid dye methyl blue as a fluorescence probe. When Deltalambda=140 nm, the synchronous fluorescence peak of methyl blue is located at 323 nm and the synchronous fluorescence intensity of the methyl blue is significantly increased in the presence of trace HSA due to the complex formed between methyl blue and HSA at pH 4.1. Under optimal conditions, the calibration graphs are linear over the range 0.03-266.0 and 266.0-665.0 microg mL(-1) for human serum albumin (HSA). Limit of determination were 0.03 microg mL(-1) for HSA. In the detection of HSA in human serum samples, this method gave values close the clinical data got from hospital.