In this chapter, we reported several portable nuclear magnetic resonance (NMR) systems implemented with silicon integrated circuits (IC). Being the initial researchers in the NMR on IC field, we firstly proposed to integrate the complex NMR electronics with the customized IC for portable NMR application with a palm size magnet. Moreover, to manage the samples inside the narrow opening of the portable magnet, we proposed the integration of the digital microfluidic device with the portable NMR system to attain electronic-automated multi-sample management scheme. With the capacitive sensing module of the droplets, the samples can be guided to the NMR sensing site sequentially to reduce labor and experimental time, which facilitates the detection and supports high-throughput sensing. Lastly, we demonstrates a NMR system with magnetic field calibration. This calibration culminates in a robust NMR sensing scheme by modulating the actual magnetic field to a steady value. Thus, the Larmor frequency can be stabilized, and the NMR sensing can work at different environment.