The selection of an appropriate reference material is crucial for correcting instrument-induced mass discrimination and validating B and Sr isotopic determinations in laser-ablation multi-collector inductively coupled plasma mass spectrometry (LA-MC-ICP-MS) analyses. This study investigates the potential of a natural tourmaline as a reference material for B and Sr isotopic determinations. Major and trace element data showed that the HGL-3 tourmaline can be classified as dravite and belongs to the alkali group tourmaline. The HGL-3 tourmaline has high B contents (36830 to 43700 μg g-1), moderate Sr contents (216 to 260 μg g-1), and low Rb/Sr ratios (< 0.0013). In-situ LA-MC-ICP-MS analyses of the HGL-3 tourmaline yielded a mean δ11B value of -12.83 ± 0.38‰ (2SD, n = 485) and a mean 87Sr/86Sr ratio of 0.70835 ± 0.00019 (2SD, n = 515). These values are identical to those of powder samples determined by thermal ionization mass spectrometry (TIMS), which gave a mean δ11B value of -12.56 ± 0.24‰ (2SD, n = 6) and a mean 87Sr/86Sr ratio of 0.70833 ± 0.00004 (2SD, n = 8). The elemental and isotopic homogeneities suggest that the HGL-3 tourmaline can be used as a suitable reference material for LA-MC-ICP-MS B and Sr isotopic determinations in tourmaline.