A new fast waveform sampling digitizing circuit based on the domino ring sampler(DRS), a switched capacitor array(SCA) chip, is presented in this paper, which is different from the traditional waveform digitizing circuit constructed with an analog to digital converter(ADC) or time to digital converter. A DRS4 chip is used as a core device in our circuit, which has a fast sampling rate up to five gigabit samples per second(GSPS). Quite satisfactory results are acquired by the preliminary performance test for this circuit board. Eight channels can be provided by one board, which has a 1 V input dynamic range for each channel. The circuit linearity is better than0.1%, the noise is less than 0.5 m V(root mean square, RMS), and its time resolution is about 50 ps. Several boards can be cascaded to construct a multi-board system. The advantages of high resolution, low cost, low power dissipation, high channel density and small size make the circuit board useful not only for physics experiments, but also for other applications. A new fast waveform sampling digitizing circuit based on the domino ring sampler (DRS), a switched capacitor array (SCA) chip, is presented in this paper, which is different from the traditional waveform digitizing circuit constructed with an analog to digital converter ) or time to digital converter. A DRS 4 chip is used as a core device in our circuit, which has a fast sampling rate up to five gigabit samples per second (GSPS). Quite satisfactory results are acquired by the preliminary performance test for this circuit Eight circuit can be provided by one board, which has 1 V input dynamic range for each channel. The circuit linearity is better than 0.1%, the noise is less than 0.5 mV (root mean square, RMS), and its advantages of high resolution, low cost, low power dissipation, high channel density and small size make the circuit board useful not only for physics experiment s, but also for other applications.