Objective To investigate the effect of cognitive behavior therapy (CBT) on the conversion of individuals with ultra-high-risk (UHR) of schizophrenia,and to find out the related influence factors.Methods Patients were randomly divided into study group (50 cases) and control group (49 cases) by the digital random table method.The study group received cognitive behavioral therapy,and the control group only got follow-up questionnaire.Structured Interview for Prodromal Syndromes (SIPS) was used to evaluate psychosis risk symptoms of each UHR individuals at baseline,3 months,6 months,12 months and 18 months respectively and the effects of CBT on conversion and related influencing factors were analyzed.Results There was no significant difference in the conversion rate (P＞ 0.05) between study group and control group after 3 months,but the conversion rate of study group was significantly lower than the control group after 6 months(6.00％ vs 20.41％,P＜0.05),12 months(10.00％ vs 24.49％,P＜0.05)and 18 months(10.00％ vs 28.57％,P＜0.05).CBT could effectively improve conditions for individuals with positive symptom (study group:5.30±3.62,5.04±3.89,4.38±4.13,5.26±3.65,5.94±4.19,control group:5.59±3.62,6.33±5.29,6.98 ±4.96,7.02±5.02,8.39±6.42,F=4.326,P=0.000) of UHR,but the improvement was not significant for negative individuals (F=1.555,P=0.215).CBT could be effective for disorganized symptom (F=6.901,P =0.010) and general symptom (F=7.752,P=0.006) as well.The poor family relationship was the risk factor of conversion to the schizophrenia (OR=3.411,95％CI=1.016-11.453,P=0.047).Conclusion CBT can effectively reduce the conversion rate of UHR individuals.CBT has a good remission effect on the positive symptoms,disintegrating symptoms and general symptoms of UHR.Family relationship affects prognosis of UHR individuals.