As　a　result　of　population　aging,　remote　electrocardiograph　(ECG)　monitoring　systems　have　increasingly　gained　attention.　The　traditional　ECG　signal　acquisition　system　has　many　limitations.　This　paper　presents　a　high-precision　sigma-delta　modulator　for　ECG　signal　acquisition.　The　circuit　is　implemented　in　a　SMIC-EE　0.18　mu　m　process.　Simulation　results　indicate　that　the　signal-to-noise　ratios　with　and　without　the　SMIC-EE　0.18　mu　m　model　are　105　and　81.2　dB,　respectively,　and　the　corresponding　effect　numbers　of　bits　are　17.15　and　13.2　bits,　respectively,　which　meet　the　requirements　of　a　remote　ECG　monitoring　system.