Local field potentials (LFPs) are electrophysiological signals with a wide range of amplitude variations from 10 μV to 1 mV, depending on several factors including electrode placement, recording depth, number and sign of brain sources contribution, brain tissue properties, etc. In this paper, the design of an adaptive gain-adjustable LFP sensing device is proposed. The device can cope with a wide range of LFP signal amplitude variations over different individuals, or over long-term chronic use in one specific subject. This LFP neural sensing device is capable of 50-100 dB dynamic gain amplification by detecting the LFP initial level (10 μ V - 1 mV). It is also miniature, light-weight, and cost effective, suitable for pre-clinical neuroscience research. The performance of the device has been successfully validated using bench-top experiments by using AC, and pre-recorded neural signals, under fixed-gain and adaptable-gain settings.