To obtain high-specific-surface-area and uniform silica nanospheres of fibrous morphologies, the hydrothermal method with and without stirring was adopted to fabricate the nanoparticles, and the fabrication mechanism as well as the influencing factors on their development were explored. Taking fibrous silica nanospheres prepared by microwave method under the same condition as references, scanning electron microscope (SEM) and transmission electron microscope (TEM) were applied to observe morphologies of the silica nanospheres developed by hydrothermal and microwave methods, Fourier transform infrared spectroscopy (FT-IR) to identify chemical compositions of the three silica nanospheres, X-ray diffractometer (XRD) to reveal the crystal structures, as well as nitrogen (N₂) adsorption-desorption isotherms to characterize the type of adsorption-desorption and pore diameters, respectively. The results indicate that nanospheres synthesized by hydrothermal method possess bigger sizes and more uniform morphologies. Especially, the effectiveness of hydrothermal method with stirring was more obvious. These three kinds of the as-prepared silica nanospheres own same chemical structures and chemical functional groups, and belong to Ⅳ adsorption-desorption isotherms with H₃ loops. Specific surface area (and pore volumes) of the three nanospheres were 480.156 m² /g(1.287 cm³ /g), 464.757 m² /g(0.654 cm³ /g) and 429.351 m² /g(0.726 cm³ /g), respectively. The pressure of the reaction system and the degree of uniformity of the reaction mother liquor collectively endow the nanospheres with special properties like morphologies and structural differences. The former accelerates uniform micellar emulsion, and the latter prompts formation of reverse micelles.