A new potassium europium borate K3EuB6O12 has been prepared using a high temperature molten salt method and structurally characterized by single crystal X-ray diffraction (SC-XRD) analyses. Its structure features a three-dimensional (3D) framework composed of isolated [B5O10](5) anions that are bridged by K+ and Eu3+ ions. In this structure, one crystallographic distinct atom site is mixed occupied by K/Eu at a molar ratio of 1:1. The self-activated photoluminescence (PL) of K3EuB6O12 was studied. The excitation spectrum covers a wide range from 322 to 466 nm, which suggests that the K3EuB6O12 phosphors can be effectively excited by a near-UV light source. The emission spectrum consists of groups of lines in the red spectral region due to the D-5(0) -> F-7(j) (j = 1, 2, 3, 4) electronic transitions of Eu3+ ions, with the most intense line at 611 nm. We may-expect that K3EuB6O12 has the potential to be a red phosphor pumped by near-UV LED chips. (C) 2016 Elsevier B.V. All rights reserved.