Abstract: According to the present invention, there are provided a green fluorescent material of the general formula:Sr.sub.1-3/2(x+y+z) Ga.sub.2 S.sub.4 :Eu.sub.x, Tb.sub.y, Sm.sub.zwhere, 0.01.ltoreq.x.ltoreq.0.2; 0.0001.ltoreq.y.ltoreq.0.007; and 0.0001.ltoreq.z.ltoreq.0.002, and a blue fluorescent material of the general formula:Ba.sub.a Mg.sub.b Al.sub.c O.sub.a+b+1.5c :Eu.sub.x, Tb.sub.v, Sm.sub.wwhere, 0.1.ltoreq.a.ltoreq.2.4; 0.1.ltoreq.b.ltoreq.5; 8.ltoreq.c.ltoreq.64; 0.01.ltoreq.x.ltoreq.0.2; 0.00005.ltoreq.v.ltoreq.0.002; and 0.00001.ltoreq.w.ltoreq.0.001.A fluorescent material of the present invention enhances the luminous efficiency of the active dynamic liquid display device.