In order to understand the effect of additive on the film forming speed and the microstructure of the micro-plasma oxide ceramic film of magnesium alloy,AZ91D die cast magnesium alloy are oxidized with a special micro-plasma apparatus,and the microstructure of ceramic film is investigated by SEM and XRD.The results show that the addition of additive containing Al to electronic solution enhances the film forming rate of oxide film,increases its density and hardness(HV) greatly and decreases the primary and s...