Three high-temperature and high-pressure sintered cassiterites doped with HfO2 were produced for use as potential reference materials for Hf isotopic analysis of cassiterite by laser ablation multi-collector inductively-coupled plasma mass spectrometry (LA-MC-ICP-MS). Ultrafine milled cassiterite powder particles (d50 = 6.3 μm) produced by wet milling were doped with HfO2 and subsequently sintered at high temperature and high-pressure to obtain homogeneous reference material for in-situ Hf isotope measurements. The sintered cassiterites have a homogeneous Hf isotopic composition at the 30 μm scale, as verified by solution nebulizer MC-ICP-MS analyses of Hf chemically separated from multiple mircodrilled sintered cassiterites, and 1065 laser ablation MC-ICP-MS analyses. The analytical results indicate a strong matrix e?ect between zircon and cassiterite during LA-MC-ICP-MS analysis. Due to low Yb and Lu contents, βHf rather than βYb was used to correct for 176Yb interference to obtain accurate 176Hf/177Hf ratios. The homogeneity of Hf isotopic compositions observed both within and between di?erent batches of sintered cassiterites suggests the potential utility of sintered cassiterite as a valuable tool for in situ isotope measurements and as an isotopic reference material.