Abstract: The structures of SOI active and passive integrated devices for RF IC applications were pro- posed, as well as the simplified processes. SOI RF LDMOS, NMOS, inductors, capacitors, resistors and varactors were integrated in the same SIMOX substrate successfully, and key devices, including LDMOS, NMOS and inductors, show excellent performances, i.e. the cutoff frequency and off-state breakdown voltage of 0.25μ m gate length LDMOS are 19.3 GHz and 16.1 V respectively; those of 0.25μ m gate length NMOS are 21.3 GHz and 4.8 V respectively; for the 2 nH, 5 nH, 10 nH spiral inductors with the proposed technique of local-dielectric-thickening, the maximum quality factors are 6.5, 5.0, 4.0, compared with those of the inductors without this technique （4.3, 3.2, 2.3）, the improvements are 77%, 58%, 49% respectively.