The basic conception of the circuit tolerance analysis was described and the factors of the parame-ter drift of devices and the methods that the parameter drift influences the quality of equipments were discussed.The essentiality that the application of circuit tolerance analysis to the process of equipments developing increases the quality of equipments design was stressed.The flows of the circuit tolerance analysis were introduced briefly，the advantages and disadvantages for three methods of the circuit tolerance analysis，the requirements of the ap-plication environments and application methods were analyzed mainly.At last，the application prospects of the circuit tolerance analysis were prospected.