High‑uranium (~4200 to 8500 ppm U) columbite-group minerals (CGMs) from No. 1 pegmatite at Dakalasu, the Chinese Altay orogen were used to assess the effect of metamictization on the UPb isotopic systematics. Backscattered electron (BSE) imaging shows that the high U concentrations are due to the U in the crystal structure itself. In the rims, the part of CGM next to cracks or pores filled by titan-uranoan fluorcalciomicrolite is altered. The microlite was likely formed via a dissolution-reprecipitation process that resulted in fractionation between U and Pb and potential discordance of the UPb isotopic systematics in the altered CGM.Raman spectroscopy indicates that the columbite samples are metamictized to various extents. However, the CGM samples dated by laser ablation – inductively coupled plasma – mass spectrometer (LA-ICP-MS) show excellent UPb age concordance, with thirty eight out of forty analyses displaying concordant UPb ages (229.0 ± 1.0 Ma to 228.1 ± 0.6 Ma) overlapping within analytical uncertainty (2σ). The alpha-decay doses are estimated to be 1.53 to 2.31 × 1015 α-decay events/mg, indicating that the CGMs are at a transition stage from being crystalline to completely metamict states. Although spatial separation between U and radiogenic Pb isotopes caused by α-recoil is inevitable, the displacement is on sub-micron scale, much smaller than the scale of laser ablation pits (43 μm) for LA-ICP-MS dating. Therefore, the UPb isotopic systematics of partially metamict, U-rich CGM may still remain concordant for CGMs that have not suffered hydrothermal alteration or metasomatism and do not contain U- or Pb-rich inclusions within the laser ablation pits. Additionally, the chemical compositions of the CGM have no control over the UPb isotopic systematics.