The dynamical characteristics of a low voltage MicroGrid from grid-connected mode to islanded mode with different distributed generation（DG） configuration schemes are analyzed by using simulation method， and the corresponding changing laws of each DG's power， voltage and frequency of MicroGrid are obtained. When micro-turbine-based synchronous generators are used as the main power support， the frequency of MicroGrid fluctuates greatly， and some DGs are disconnected from the grid by the low frequency relays， which is not beneficial to stable operation of the MicroGrid. After increasing storage devices， the storage devices play an important role in MicroGrid control， and the inverter of battery using droop control could provide fast power support for the islanded MicroGrid， and can damp the voltage and frequency fluctuations caused by the slow dynamical response of gas turbine efficiently.