Abstract： Objective To investigate the association of Cys-C level and forget pattern mild cognitive impairment and analyze the risk factors for aMIC. Methods Proceed the age, sex, standard of culture, the history of smoking and drinking, diabetes, blood fat, creatinine, high biood pressure, cerebral blood disease, the level of Cys-C and the level of cognitive impairment for 249 effective case about aMCI group and control group. Arrange the possible influence factor, investigate the affect between Cys-C level and forget pattern mild cognitive impairment. Results 0 in defferent Cys-C level, the distribution of age, standard of culture, the history of smoking and drinking, diabetes, high biood pressure, anomaly blood fat, anomaly creatinine are significant difference(P<0.05)the level of Cys-C in aMCI group and control group are significant difference(P<0.05). The level of Cys-C aMCI group and MMSE(r=-0.319),MOCA (r=-0.583), and score visuospatial executive(r=-0.301), naming(r=-0.265), attention(r=-0.254), delayed recall of MOCA(r<0, P<0.05),The level of Cys-C raising,incidence of aMCI increasing(χ2=14.23, P<0.01);Logistic regression analysis shoud different level of Cys-C、standard of culture ,the history of smoking and drinking, diabetes , blood fat,are the single risk for aMCI. Conclusion The high Cys-C level is a risk factor for aMIC.