Silicon pressure transducers feature miniaturization and high sensitivity. The pressurerange for nimiature pressure transducers has been as low as 1 kPa by now. In the development of highsensitivity pressure transducer,the inprovement of diaphragm structure has been playing an importantrole. lntroduced in this paper is the beam-diaphragm (island)structure, first proposed by the authors in1989. Also introduced are two similar structures proposed by TUB and Honeywell in 1993 and 1992,respectively. 1 kPa pressure range has been achieved by all these three structure.