In this paper islanding operation of a voltage source converter based DG system with fuzzy logic controller is presented. In the grid-connected mode, a microgrid including its loads and DG units is connected to the main grid at the point of common coupling (PCC), the voltage-sourced converter is operated in the active and reactive power (PQ) control mode, by using conventional control scheme to control the active and reactive power exchange with the grid. In the islanded mode, the proposed ANFIS is used to control the voltage of the islanded system despite the load variability and uncertainties. The salient features of the proposed ANFIS are: 1) efficient to deal with the nonlinear systems 2) design does not depend on the mathematical model of the system and 3) less sensitive to the parameters variation than the conventional controllers. The frequency of the islanded system is dictated through the use of an internal oscillator. The simulation results are presented by using Matlab/simulink platform. The dynamic response of the DG system using the ANFIS have good transient behaviors compairing to the FLC and PI controllers.