High luminous efficacy, high-color-rendering index (CRI), single-phased and single Eu2+ doped warm white-light phosphors Ca-2(BO3)(1-x)(PO4) Cl-x were synthesized by controlling anion substitution systematically. The anionic polyhedron substitution of PO4 for BO3 causes a great distortion of the host lattice, which enables the tuning of luminescent properties. An additional distinct emission peaking at 462 nm (in addition to 577 nm of Ca2BO3Cl:Eu2+) was observed under the same excitation when PO43 was introduced. Therefore, with the crystal structure evolution, the ratio blue/yellow was changed by adjusting the ratio of BO3/PO4, which provides a new way for developing a high CRI warm white-light phosphor. The internal quantum efficiency (IQE) of the Ca-2(BO3)(0.64)(PO4)(0.36)Cl:Eu2+ phosphor was 64.0%. The warm white light-emitting diode (w-LED) was fabricated with Ca-2(BO3)(0.64)(PO4)(0.36)Cl: Eu2+ phosphor and a 380 nm-emitting InGaN chip, which exhibited promising properties, such as the high Ra (83.4), the low correlated color temperature (3907 K) and high luminous efficacy n(J) (30.4 lm/W). Importantly, the w-LED shows a greater R9 = 39.3 versus R9 = 14.3 of commercial YAG:Ce3+. These phenomenon demonstrates that Ca-2(BO3)(1-x)(PO4) xCl: Eu2+ as a warm white-light phosphor will have a great prospect of application in indoor lighting. (C) 2017 Elsevier B.V. All rights reserved.