Pixel reset circuit is an important component of CMOS image sensor

whose characteristics affect the image quality directly.The performances of CMOS image sensor

such as dynamic range

anti-blooming

image lag and non-linearity

are analyzed.This paper also discusses the methods to improve performance through reset circuit.In this paper

two kinds of hard reset circuit with anti-blooming circuit are designed

one is the use of conventional cross-coupled configuration to implement reset level shift

the other is based on improved latch configuration with adding compensation transistor of threshold value

both schemes with different advantages and disadvantages adapt for different applications.The simulations reveal that both circuits implement can enhance dynamic range by 2dB~3dB

increase the ability of anti-blooming

and remove image lag and non-linearity at low-light level.