A phosphor is represented by below formula: AaBbCcDdEe:Mm wherein, M represents at least one activator selected from Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb and combinations thereof; A represents at least one element selected from Ca2+, Sr2+, Ba2+ and combinations thereof; B represents C4+, Si4+ or Ge4+; C represents B3+, Al3+ or Ga3+; D and E each independently represent at least one element selected from N, O, F and combinations thereof; m+a=2; 0.00001≦m≦0.1; 0.5≦b+c≦8; and 0.5≦d+e≦10. The phosphor has a color render index of greater than 50 and is suitable to be applied in a white LED to improve the color rendering property of the white light. A method of preparing the phosphor is also provided.