The third-order nonlinear optical properties of Bi2S3 nanocrystals doped in sodium borosilicate glass are measured by Z-scan technique. The microstructures of the glass are characterized by means of X-ray diffraction, transmission electron microscopy, scanning transmission electron microscopy, energy dispersion X-ray spectra, and high-resolution transmission electron microscopy. The results show that the Bi2S3 nanocrystals ranging from 10 to 30 nm are determined to be of the orthorhombic crystalline phase, and the third-order optical nonlinear refractive index gamma, absorption coefficient beta, and susceptibility chi((3)) of the glass are determined to be 2.56 x 10(-16) m(2) W-1, 4.13 x 10(-1) mW(-1), and 1.43 x 10(-10) esu, respectively. 2010 Elsevier Ltd. All rights reserved.