The development status of CMOS readout circuits (ROIC) of mercury cadmium telluride focal plane array devices were reviewed by summarizing and analyzing some papers published in recent years. The related concepts of ROIC were discussed. The unit structures of some preamplifier circuits were listed and their operating characteristics were analyzed. The effects of some factors such as integration time, integration capacitance, multiplexing and etc. on the design of ROIC were presented.