Improved Extinction Ratio of 25 dB was demonstrated in silicon based optical modulators on CMOS platform in China. The measurement results agree with the simulation, followed by a discussion about the effects of both propagation loss in Mach-Zehnder arms and power ratio at beam splitters and combiners. The analyses indicate that many considerations have to be taken into design and development of the compatible fabrication of these integrated silicon photonics, especially for the improved extinction ratio of optical modulators. In this summary, we propose the integrated optical modulators in SOI by use of the compatible CMOS processes under the modern CMOS foundry in Chinese homeland. And the measured results were shown, the fast response modulator with the data transmission rate of 10 Gbps.