Precise assessment of the operation and vulnerabil.ity in microgrid at a certain time in the future contributes to find outthe weak point in the system in time and realize self.healing opera.tion of microgrid.Based on the characteristics of microgrid, a vulner.ability pre.assessment method for microgrid is proposed.Firstly, thedefinition of microgrid's vulnerability is given.Then, according tothe occurrence probability of every influential event and severity ofcorresponding results, a vulnerability index system is established,mainly including indices of generation capacity adequacy and indi.ces of power supply vulnerability.Eventually, the procedures andspecific steps of vulnerability pre.assessment for microgrid are pre.sented, and its effectiveness and validity is verified by case studies.