The Ba 3 MgSi 2 O 8 :Eu 2+ , Mn 2+ phosphors are synthesized through combustion process with varying mixture ratio of citric acid and ethylene glycol used as a fuel to the used precursors. They have the mean particle size of 200nm and the spherical shape. The Ba 3 MgSi 2 O 8 :Eu 2+ , Mn 2+ phosphors show three emission colors: the blue color of 433nm from Eu 2+ (I) substituted by Ba 2+ (I) site, the green color of 500nm from Eu 2+ (II, III) substituted by Ba 2+ (II, III) site, the red color of 610nm from Mn 2+ (I, II, III). Compared with a solid-state method-prepared sample, the emission peaks of three emission bands are shifted to about 10nm towards the shorter wavelength. This blue shift is explained by quantum size effect. The relative intensity ratios of the green band to the blue band are significantly increased as the increasing amount of fuel suggesting that Eu 2+ ions in our sample preferably occupy Ba 2+ (II, III) sites related to the green emissions.