Yellow silver nanoparticles in water phase were prepared by microwave synthesis method. Study found that there is a fluorescence peak at 465 nm and a strongest resonance scattering peak at 460 nm for the nanoparticles. The resonance scattering intensity at 465 nm I(460 nm). fluorescence intensity at 465 nm F(465)(nm) and absorbance at 455 nm A(455 nm) were found linear to the concentration c(Ag) in the range from 0 to 3.5x10(-4)mol/L Ag, with linear regression equation for I(460 nm)=48.1x10(4) c(Ag)+3.69 and F(465 nm)=28.7x10(4)c(Ag)+3.50 and A(455 nm)1.23x10(4)c(Ag)+0.01, their regression coefficient for 0.9976, 0.9954 and 0.9957, respectively. When the c(Ag) was over 3.5x10(-4)mol/L, the resonance scattering peak and fluorescence peak of 465 nm take place red-shift and display luminescence quenching, but the absorption peak place does not change and the absorption intensity enhances. The paper reports the spectral properties of silver nanoparticles in water phase, and offers the principle of interface luminescence electron to state the luminescence effect of silver nanoparticles.