In this work, shear thickening (ST) performance of a novel suspension of porous silica nanoparticles was systematically studied. The porous silica nanoparticles which were synthesized by using CTAB as a pore-forming agent were dispersed into ethylene glycol to form shear thickening fluid (STF). Both the steady and oscillatory shear rheological properties of the STF were characterized. The STF showed distinct ST effects when the concentration of the porous nanoparticles was only 42.5 wt%. This value was much lower than the previously reported STF prepared by non-porous particles. The viscosity increased from 0.80 to 14.3 Pa s by increasing the shear rate from 0.1 to 49.4 s(-1), while a noticeable overall downward trend with a high initial viscosity was found in the prepared suspension of non-porous silica. The results indicated that porous nature of the silica nanoparticles could remarkably influence the ST effect. A possible enhancing mechanism was proposed and it was found that the difference of macroscopic rheology behavior was mainly according to interfacial interaction between the porous silica nanoparticles. This work provided valuable information for understanding the relationship between the porous characteristics and ST behavior.