Abstract： Objective To explore the correlation between sleep disorder and cognitive dysfunction in patients with persistent postural-perceptual dizziness(PPPD).Methods A total of 81 PPPD patients who were treated in the our hospital from December 2019 to June 2020 were enrolled as the study group,in addition,81 patients with high incidence of dizziness treated in the our hospital from December 2019 to March 2020 were as the control group,although who didn't take any psychotropic drugs due to the remission of dizziness symptoms.The patients'sleep quality and cognitive ability were measured by the Mini-Mental State Examination(MMSE),the Montreal Cognitive Assessment(MoCA)and the Pittsburgh Sleep Quality Index(PSQI)were assessed,and the correlation between sleep and cognition was analyzed.Results There were significant differences in the four dimension(memory,attention,calculation and recall ability)and the total score of MMSE between the study group and the control group(P＜0.05).There was no significant difference in the scores of orientation and language ability between groups(P＞0.05).The dimension(attention and concentration,memory,abstract thinking)and total scores of MOCA in the study group were significantly lower than those of the control group(P＜0.05).The scores of executive function,language,visual structure skills,calculation,and directional force in the study group were comparable to those of the control group(P＞0.05).The six dimensions(subjective sleep quality,time before falling asleep,sleep duration,sleep efficiency,sleep disturbance and daytime dysfunction)and total scores of PSQI were significantly higher than those of the control group(P＜0.05),but the dimensions score of PSQI for hypnotic drug was similar(P＞0.05).Conclusion Patients with PPPD generally have moderate sleep disorders,and there is a significant correlation between sleep time and sleep quality with cognitive function.