In this study, polymethylmethacrylate (PMMA) bone cement (BC) was modified with ultra-fine glass fibers (UFGF) and nano-hydroxapatite (nano-HAP) synthesized by hydrothermal method. The results show that when the contents of both UFGF and nano-HAP powders are about 5%, the ultimate tensile strength (UTS), ultimate impact toughness (UIT), tensile strain (TS), and elastic modulus (EM) have been promoted a lot. The interface bond was improved by silicane treatment. Pre-grinding mixture of PMMA, UFGF, and nano-HAP can largely improve the mechanical property of PMMA. The PMMA modified with UFGF and HAP has better bioactivity than that modified with pure UFGF when they share the same content. Nano-HAP powder and modified PMMA were characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR).