Wet gel electrodes have been widely used for electroencephalography(EEG)signal recording,which generally causes skin abrasion and longer preparation time.In this paper,we present soft ionic-hydrogel based electrodes to overcome such drawbacks.In order to conveniently measure the EEG signals,we design the claw-like and patch-like structures for robust connection between metal(Ag/AgCl)electrodes and skin scalps.Next,we experimentally show that the soft ionic-hydrogel based electrodes have similar performance with the conventional wet gel electrodes in terms of the short-circuit noise,electrical impedance,and skin-electrode contact impedance on unprepared human skin,significantly better than dry electrodes and water-based electrodes.We further perform the EEG measurements and steady-state visual evoked potentials(SSVEP)experiments with five subjects to verify the effectiveness of the soft ionic-hydrogel based electrodes.The experimental results demonstrate that our developed soft ionic-hydrogel electrodes can record high-quality EEG signals in a fast and clean way,being a compelling option for EEG-based brain-computer interfaces.