To investigate spin susceptibility in a superconducting (SC) state, we measured the ${}^{125}\mathrm{Te}$-NMR Knight shifts at magnetic fields ($H$) up to 6.5 T along the $b$ and $c$ axes of single-crystal ${\mathrm{UTe}}_2$, a promising candidate for a spin-triplet superconductor. In the SC state, the Knight shifts along the $b$ and $c$ axes ($K_b$ and $K_c$, respectively) decreased slightly, and the decrease in $K_b$ was almost constant up to 6.5 T. The reduction in $K_c$ decreased with increasing $H$, and $K_c$ was unchanged through the SC transition temperature at 5.5 T, excluding the possibility of spin-singlet pairing. Our results indicate that spin susceptibilities along the $b$ and $c$ axes slightly decrease in the SC state in low $H$, and the $H$ response of SC spin susceptibility is anisotropic on the $bc$ plane. We discuss the possible $\mathit{d}$-vector state within the spin-triplet scenario and suggest that the dominant $\mathit{d}$-vector component for the case of $H\parallel b$ changes above 13 T, where $T_{\mathrm{c}}$ increases with increasing $H$.

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• Magnetic anisotropy
• Spin-triplet pairing
• Superconductivity
• p-wave
• Ferromagnetic superconductors
• Nuclear magnetic resonance