A borosilicate sol-gel solution is synthesized using a mixture of methyltriethoxysilane, dimethyldiethoxysilane, and boric acid. SiBOC gel fibers are produced from the as-synthesized sol-gel solution using a spinning apparatus. Subsequently, SiBOC glass fibers are prepared through pyrolysis under argon atmosphere at 1000 degrees C and 1200 degrees C. Mechanical properties of the SiBOC glass fibers are studied by measuring the tensile strength and the elastic modulus. The results show a high tensile strength -1300 and 1058MPa, and a high Young modulus -79 and 95.5GPa, for the fibers prepared at 1000 degrees C and 1200 degrees C, respectively. Furthermore, alkali resistance of the SiBOC fibers is investigated by measuring the tensile strength after soaking them for 20h in NaOH and Ca(OH)(2) solutions at 100 degrees C. For comparison, the same measurements are performed on commercial AR and E glass fibers. The SiBOC fibers show excellent alkaline resistance and perform better than commercial AR fibers. Indeed, SiBOC fibers retain 80%-90% of the initial strength after Ca(OH)(2) attack.