We have carried out a 93Nb nuclear magnetic resonance (NMR) study on a quasi-one-dimensionalsuperconductor, Nb3Te4, and the isostructural intercalated compounds AxNb3Te4 (A = Inand Zn), to understand the varied impact of metal–atom intercalationsinto the hexagonal infinite tunnels on the charge density wave andsuperconductivity formations. Below the Peierls transition temperature TCfor each of the compounds, the nuclear spin–lattice relaxation rate(T1 T)−1exhibited a significant decrease which originates from the partialFermi surface quenching associated with the Peierls transition. Withx ≃ 0.1 introductionsof In and Zn, (T1 T)−1was greatly enhanced from 10 s−1K−1 to 20 and 18 s−1K−1, respectively.On the other hand, the nuclear quadrupole frequency νQwas diminished from 0.98 MHz to 0.63 and 0.74 MHz, respectively.A remarkable difference between the In and Zn intercalations wasfound in the extent of decrease in the isotropic Knight shift Kiso:from 0.237 to 0.216% for In; and to 0.166% for Zn. Based upon the d bandstructures predicted theoretically, we have indicated that the variations in theNMR parameters can be explained consistently, if the extent of hole dopingby a Zn atom is much larger than that by an In atom. The heavy holedoping by Zn intercalation changes the dominant subband at EF from dyz,zx to dx2 −y2,giving rise to a distinct nesting condition of the Fermi surface.