Addition of high energy boron into the liquid fuel is an effective method to improve the energy density of the blended fuel. However， the added content of boron is limited， due to the dramatic increase in the viscosity of the blended fuel. So it is important to increase the boron content as much as possible without obvious viscosity increase. Four organosilanes including propyltrimethoxysilane （C3-silane）， octyltrimethoxysilane （C8-silane）， dodecyltrimethoxysilane （C12-silane） and hexadecyltrimethoxysilanes （C16-silane） were used to modify boron particles. First， the modified boron particles were characterized by scanning electron microscopy， contact angle measurement， X-ray diffraction， particle size analysis （using dynamic laser scattering） and thermogravimetric analysis. Then the rheological properties of organosilane modified boron/JP-10 blend fuels were investigated. Finally， the effect of temperature on the apparent viscosities at different shear rates was studied. The results show that boric acid on the boron surface was removed upon surface modification with organosilanes and the surface characteristics of boron powder were transformed from hydrophilicity to hydrophobicity. The content of organosilane was less than 1.5% in the organosilane modified boron particles， which would have marginal effect on the total heat value. Organosilane modified boron/JP-10 blend fuels with solids content of 50% showed good fluidity and their apparent viscosities were lower than 0.3 Pa·s at 25 ℃ and 100 s^-1 of shear rate. Keeping other conditions the same， the apparent viscosity of blend fuels depends on the length of side chain alkyl group of organosilane： C3-silane>C8-silane≈C12-silane≈C16-silane. Organosilane modified boron/JP-10 blend fuels showed shear-thinning characteristics and the relationship between the apparent viscosity and the shear rate could be well fitted by power-law equation. The apparent viscosity of blend fuels depends strongly on the temperature and their relationship could be well expressed by Arrhenius equation. The shear activation energy of blend fuels increases with increasing the length of side chain alkyl group of organosilane coated on the boron.