Microgrid allows flexible integration of distributed generation using renewable energy sources into the conventional centralized power system with the additional benefit of islanded mode operation Research efforts on DC microgrids have gained momentum in the recent years, mainly due to its inherent advantages compared to AC microgrids. Several DC renewable energy sources are connected to a common DC bus in a DC microgrid using DC-DC converters. When converters of different ratings are connected in parallel, it is required that the load demand is shared by the converters proportional to their power ratings. This will ensure that individual converters are not overstressed and the connected load is optimally shared. This paper investigates a droop control strategy for parallel DC-DC converters using virtual output impedance method for optimum load sharing. Simulation of the control strategy has been done for two parallel connected buck converters and the results show the optimum load sharing between the two converters.