beta-In2-xAlxS3 thin films have been grown on glass substrate by chemical bath deposition for different value of Al concentration y = (([Al])/([In]))(sol) (0 <= y <= 5 at.%). Samples have been characterized using X-ray diffraction, atomic force microscopy and by spectrophotometric measurements. The influence of the increase of y ratio in the structural and optical properties are described and discussed in terms of crystallinity improvement. In order to increase film thickness of beta-In2-xAlxS3, we have been realized multi-deposition system. The structural, the surface morphology as well as the optical properties seem to be improved as the film thickness is of about 1200 nm.