[en] The subsolidus phase relations of the ternary system ZnO-B₂O₃-P₂O₅ were investigated by means of X-ray diffraction (XRD). Seven binary compounds, 1 ternary compound and 10 three-phase regions were determined in this system. The phase diagrams of the pseudo-binary systems Zn₃(BO₃)₂-ZnO, Zn₃(PO₄)₂-ZnO and Zn₃BPO₇-ZnO were also determined through XRD and differential thermal analysis (DTA) methods. They all form eutectic systems with eutectic temperature about 1000 deg. C. Zn₃(BO₃)₂ and Zn₃(PO₄)₂ are not suitable fluxes, while Zn₃BPO₇ might be a suitable flux for ZnO crystal growth