Objective : To explore the adverse effects of mild traumatic brain injury ( MTBI) on the memory monito- ring function of patients． Methods : This study adopted a paired control research method，combined neuropsycho- logical background tests and memory monitoring task ( feeling of knowing，FOK) to conduct cognitive assessments on two groups of subjects: the patient group ( n = 42) and the matched control group ( n = 42) ． Results : In neuropsychological background test，the patients' performance in digit span test，Stroop color task，digit link task and auditory verbal learning test were significantly lower than those in the control group ( P＜0. 05) ．In addition，there was significant difference in accuracy of FOK task between the two groups ( P ＜0. 05) ．The ratio of right judge- ment / right recognition was relatively high in the control group，while the ratio of correct judgement /wrong recogni- tion was relatively high in the patient group． Conclusion This study confirms that memory impairment in MTBI patients is centered on damage to memory monitoring function．Moreover，the damage to attention，execution，and item content memory abilities in MTBI patients are important driving factors for their memory monitoring dysfunction．