Abstract: The FMEAES(Failure Model Effect Analysis Expert System) that applies the artificial intelligent is introduced. It is established based on expert knowledge and function/hardware reasoning combined with fault simulation of the EDA(Electronic Design Automation) and supported by the reliability CAD and the reliability information system and the fault diagnosis expert system to extend the knowledge base and to enhance the FMEAES's capability. The expert system structure and function, the function of the elements including the pretreatment part, the core of the FMEAES and the posttreatment part and the relationship of the elements of FMEAES is described.Then the function of the failure model selection and the fault simulation using the EDA software and the reasoning and analysis flow to perform function FMEA and hardware FMEA of the FMEAES is discussed in detail.