OBJECTIVES: People at ultra-high risk for psychosis have heterogenous character and different long-term outcomes. We divided ultra-high risk subjects into two subgroups by presence of familial history and tried to find different pattern of functional connectivity of the default mode network (DMN) between the two groups in order to examine the effects familial loading. METHODS: Eleven subjects at clinical-high risk (CHR) group with familial history of psychiatric illness and nineteen subjects of CHR group without familial history were recruited. All the subjects were scanned using resting-state functional magnetic resonance imaging. A posterior cingulate cortex was the seed region of the analysis, and the DMN of the both high risk group were analyzed with voxel-wise two sample T test. RESULTS: The CHR group with familial history showed greater functional connectivity in the precuneus area in contrast with the other high risk subjects (peak-level t=5.49, p<0.001). There were no significant differences in total score on the Positive and Negative Syndrome Scale and Scales of Psychosis-risk Syndrome between the two groups. CONCLUSION: The study suggests that the abnormalities of functional connectivity between precuneus and posterior cingulate area may be associated with the genetic vulnerability of high risk trait.