The nanocrystalline silicon embedded in SiNx (nc-Si-SiNx) film was prepared by radio-frequency (RF) magnetron sputtering technique and thermal annealing. The film of 200 nm thick was deposited on silica glass slice. The average diameter of nanocrystalline silicon in the film annealed at 800 ℃ for three hours was about 1.7 nm according to X-ray diffraction (XRD) spectrum. The passive mode-locking operation of a flash-lamp pumped Nd∶YAG laser was achieved by inserting the nc-Si-SiNx film as the saturable absorber into the plane-concave resonator. A single pulse train with average pulse duration of 32 ps and energy of 25 mJ was obtained when the cavity length was 120 cm. The sustained time of a single pulse train was about 480 ns and the modulation depth of mode-locking was nearly 100%. The nc-Si-SiNx film passive mode-locking at 1.06 μm laser was mainly ascribed to two-photon saturable absorption and fast energy relaxation processes of carriers excited by laser in the nanocrystalline silicon since the energy band gap of the nanocrystalline silicon affected by the quantum confinement related effects was larger than the photon energy of 1.06 μm laser.