A low-light-level CMOS image sensor with Capacitive Trans-impedance Amplifier（CTIA） pixel circuit and Delta Double Sampling（DDS） was proposed. By using CTIA circuit, stable bias voltage of the photodiode and high injection ratio can be realized, and the weak signal in low-light-level condition can be readout; Meanwhile, an off-chip digital DDS was used to reduce the fixed pattern noise (FPN) which was realizing the subtraction algorithm between the reset signal and pixel signal after A/D conversion off-chip, and improve the image quality of the low-light-level CIS. This low-light-level CMOS image sensor (CIS) based on CTIA pixel circuit was implemented in the 0.35 μm standard CMOS technology. The pixel array was 256×256, and the pixel size was 16 μm×16 μm. The experimental results show that this low-light-level CIS can capture recognizable images with the illumination down to 0.05 lx.