The design and characterization of high conversion-gain pixels in 180nm CMOS process will be presented. Pixel output-referred conversion gain as high as 163.4uV/e- and read noise as low as 1.44e- rms are achieved. Low dark current level around 38 pA/cm2 is measured at 60°C. Comparison between proposed devices and baseline pixel regarding device structure and characterization results will also be discussed.