The present invention relates to an oxynitride luminescent material, a preparation method, and an LED light source manufactured thereby. Chemical compositions of the luminescent material are M1 a M2 b Si c O d N e:xEu 2+, M1 being one or two or a combination of more than two of elements: Mg, Ca, Sr, Ba, and Zn; M2 being one or a combination of two of elements: Tb and Tm; a, b, c, d, e and x being molar coefficients of atoms, and 1≦a≦4, 0.001≦b≦0.6, 0.8≦c≦1.2, 0