New quaternary tellurides, Cs2Ge3M6Te14 (M = Ga, In), were discovered by solid-state reactions. These compounds crystallize in space group P3 (m) over barl (No. 164), with a = b = 8.2475(2) angstrom, c = 14.2734(8) angstrom, and V = 840.82(6) angstrom(3) (Z = 1) for Cs2Ge3Ga6Te14 (1) and a = b = 8.5404(2) angstrom, c = 14.6766(8) angstrom, and V = 927.07(6) angstrom(3) (Z = 1) for Cs2Ge3In6Te14 (2). The remarkable structural feature is the novel three-dimensional [Ge3M6Te14](2-) anionic framework made by condensed In6Te14 (or Ga6Te14) layers that are connected alternately by dimeric Ge23+Te6 units and Ge2+Te6 octahedra along the c direction. The presence of Ge centers with different oxidation states is also supported by the results of the electron localization function calculation and X-ray photoelectron spectroscopy measurement.