Abstract: In this paper , using the generalized Huyg en-s Fr esnel diffr action integral, the fo cusing properties of tw isted Gaussian-Schell model beams through an aperture lens have been studied in detail.Numerical calculation r esults demonstr ate that the focusing properties of tw isted Gaussian Schell-model beams are dependent on Fresnel number of optical systems, trucat ion parameter , coherent paramenter and twisted parameter.