The nano-sized MoO3/PMMA hybrid material was prepared by in-situ polymerization method. XRD patterns show that the hybrid material is amorphous. SEM indicates that the morphology of fracture plane of the hybrid material is different when MoO3 content is varied in the hybrid materials, and the fragility increase with the increase of MoO3 content. EDS reveals that the content of Mo is 1.09%. It is found that the transmissivity, solubility, hardness and fracture strength of the hybrid materials decrease with the increase of MoO3 content.