ZnS quantum_dots were assembled in synthetic chrysotile nano-tubes based on the ultrasonic chemical method, and the attributes of the assembled samples were studied by such means as powder X-ray diffraction (XRD), transmission electron microscopy (TEM) and ultraviolet-visible spectroscopy (UV-Vis). Transmission electron microscope (TEM) observation shows that ZnS quantum_dots were assembled in the nano-tubes of synthetic chrysotile. XRD has revealed that the ZnS quantum-dots in the nano-tubes are β-ZnS and their average crystal granularity is 4.2 nm. The optical absorption side of the ZnS quantum-dots is shifted to the longer wavelength where the red shift is 5 nm.