Objective:To investigate the behavioral, electroencephalographic, and cognitive functional differences in drug-resistant epileptic rat models of cognitive impairment prepared by intraperitoneal injection of lithium chloride-pilocarpine followed by intracranial injection of pilocarpine or carbamylcholine.Methods:One hundred and sixty adult male SD rats were randomly divided into normal control group ( n=10), lithium chloride-pilocarpine group (establishing epileptic rat models by intraperitoneal injection of lithium chloride-pilocarpine, n=50), pilocarpine-pilocarpine group (intracranial injection of pilocarpine after intraperitoneal injection of lithium chloride-pilocarpine, n=50)and pilocarpine-carbamylcholine group (intracranial injection of carbamylcholine after intraperitoneal injection of lithium chloride-pilocarpine, n=50). Frequency and duration of spontaneously recurrent seizures (SRSs) were observed by video monitoring system, and 2 weeks after that, phenobarbital and phenytoin sodium were injected intraperitoneally to screen drug-resistant models. Frequency and amplitude of the epileptic waves in EEG were recorded by BL-420 Bio-signal Acquisition and Processing System. Novel object recognition experiment was used to detect the novel exploration, Y-maze free exploration experiment and new and different arm experiment were used to detect the spatial recognition and memory ability, and Morris water maze experiment was used to detect the spatial memory ability. Results:(1) Twenty-four rats (48.00%) survived in the lithium chloride-pilocarpine group, 25 (78.00%) in the pilocarpine-pilocarpine group, and 21 (65.62%) in the pilocarpine-carbamylcholine group; and ultimately 7, 9, and 8 drug-resistant epileptic rat models were identified, respectively; frequency and duration of SRSs in the pilocarpine-pilocarpine group and pilocarpine-carbamylcholine group were significantly higher/longer than those in the lithium chloride-pilocarpine group ( P<0.05). (2) The pilocarpine-pilocarpine group and pilocarpine-carbamylcholine group had significantly higher amplitude of the epileptic waves in EEG compared with the lithium chloride-pilocarpine group ( P<0.05); the frequency of the epileptic waves in EEG increased gradually in the lithium chloride-pilocarpine group, pilocarpine-pilocarpine group, and pilocarpine-carbamylcholine group ( P<0.05). (3) Discrimination index, accuracy, ratio of distance traveled in novel arm to total distance, and time of novel arm entries gradually decreased in the normal control group, lithium chloride-pilocarpine group, pilocarpine-pilocarpine group, and pilocarpine-carbamylcholine group, with significant differences ( P<0.05). (4) Compared with the normal control group, the pilocarpine-pilocarpine group and pilocarpine-carbamylcholine group had significantly decreased frequency in crossing the original platform ( P<0.05); compared with the normal control group, lithium-pilocarpine chloride group and pilocarpine-pilocarpine group, the pilocarpine-carbamylcholine group had statistically shorter distance of target quadrant activity ( P<0.05); number of entries in the target quadrant gradually decreased in the normal control group, lithium chloride-pilocarpine group, pilocarpine-pilocarpine group, and pilocarpine-carbamylcholine group, with significant differences ( P<0.05). Conclusion:Drug-resistant epileptic rat models established by intracranial injection of carbamylcholine after intraperitoneal injection of lithium chloride-pilocarpine have high survival rate, high SRSs rate, and severe cognitive impairment, which is suitable for studying drug-resistant epilepsy combined with cognitive impairment.