Absolute band gaps of the two-dimensional triangular-lattice photonic crystals consisting of Ge rods are calculated with the finite-difference time-domain method. Through calculating the band structures of the triangular-lattice photonic crystal consisting of hollow circular Ge rods,it is found that the TM-polarized and TE-polarized photonic band gaps can be overlapped,and an absolute photonic band gap can be obtained. A large absolute band gap of 0.074 (2πc/a) can be obtained for the structures with a triangular lattice of hollow triangular Ge rods immersed in air,corresponding to 16.2% of the central frequency.