This thesis presents a design methodology of a low-power and low-noise integrated front-end readout circuits for radiation detection. Since a charge sensitive amplifier (CSA) and a pulse shaper are essential circuit units in the low-power and low noise front-end readout circuits, this thesis provides how to design the low power low noise CSA and the pulse shaper. The CSA can allow the electrons generated from the detector to integrate on a feedback capacitor of a CSA. The main function of a CSA is to amplify the input signal charge generated from the detector into the output voltage step signal. The input transistor optimization can significantly reduce the noise impact on the whole system so it can help the front-end readout circuit increase the sensitivity in order to detect smaller electrons generated from the detector. The pulse shaper is a high order semi-Gaussian pulse shaping filter. The main function of the pulse shaper is to filter the output signal and noise from the CSA in order to maximize signal-to-noise ratio and obtain the lowest equivalent noise charge (ENC). In this thesis, the semi-Gaussian pulse shaper with ICON cells can achieve a longer time constant in order to minimize the noise in the circuitry.