Calcium alginate fibers and nano-silica/calcium alginate blend fibers were prepared by the mean of wet spinning at the same spinning condition. The effect of nano-particles SiO2 on the structure and properties of alginate fibers were studied via many tests. The results showed that the tenacity of blend fibers increased with the growth of the content of SiO2 ranging from 1% to 5%, however, the tenacity of fibers became worse when the content of SiO2 was more than 5%. The effect of SiO2 content on hardness and tribological properties of the calcium alginate fiber was studied. The morphologies of the fibers surfaces were examined with a Scanning Electron Microscope (SEM). The result showed that the surface of blend fibers was still smooth when the consent of SiO2 not up to 7%, the best surface was obtained when SiO2 content was 5%. The incorporation of SiO2 also affected the absorption property of alginate fiber and made it decrease with the increase of SiO2 content. The structures of calcium alginate fibers and nano-silica/calcium alginate blend fibers were studied by infrared spectrum.