Objective Neurobiological mechanisms underlying primary insomnia(PI)are still elusive.The aim of the present study was to provide additional information in functional integration aberration of PI patients with insular-based functional connectivity(FC).Methods With the resting-state fMRI data acquired from 57 PI patients and 46 healthy control subjects,a two-sample t-test was performed on individual FC correlation maps from the PI and healthy control groups to explore the abnormal cortical connectivity patterns between the insular and the voxels in PI.Additionally,the relationship between aberrant connectivity and clinical symptoms was evaluated with Pearson correlation analysis Results PI patients show enhanced connectivity between the left insula with the right frontal sup orb,right anterior cingulate cortex,bilateral thalamus and left precuneus as well as decreased connectivity with the left middle temporal gyrus and right fusiform(p<0.05,AlphaSim corrected).Correlation analysis indicated that there is a significant negative correlation between the stronger functional connectivity(right anterior cingulate cortex and bilateral thalamus)with the SDS score,as well as(right anterior cingulate cortex)with the SAS score.In addition,a positive correlation between the weakened functional connectivity(right fusiform)with SDS score was found,as well as(left middle temporal gyrus)with the SAS score Conclusion Our study showed that the increased connectivity regions with insula were mainly in the emotional circle and decreased connectivity in cognitive-related regions.Our study provides additional evidence from the functional integration view to help us to understand the possible underlying neural mechanisms of primary insomnia.