Objective To compare 6 sub-function scale differences of frontal lobe function rating scale or a Frontal Assessment Battery(FAB)among patients with two subtypes of vascular cognitive impairment(VCI) to provide clues for the distinctive intervention and disease prevention and control of patients with two subtypes.Methods Totally 220 non-dementia vascular cognitive impairment (NDVCI)patients and 68 patients with vascular dementia(VaD)with final diagnosis were selected.The overall function and six sub-function scores were tested by FAB.Analyzing the score difference and probing a progress tendency from NDVCI to VaD were performed.Results The scores of frontal lobe function rating scale were higher in NDVCI(14.0 ± 2.8)than in VaD (9.5±2.0) patients with significant difference(t =29.92,P =0.00).The scales of frontal lobe function rating score of conceptualization ability (t =6.24,P =0.00),intelligence flexibility (t =7.00,P =0.00),antiinterference ability(t =7.21,P =0.00) and attention suppression(t =5.32,P =0.00) were lower in VaD group than in NDVCI group.The conceptualization weight capacity was significantly lower in VaD group than in NDVCI group(0.04 versus 0.32).Conclusions During a transitive process from NDVCI to VaD,it is important to focus on the mutation and deterioration of conceptualization capacity.