The effect of modified nanoTiO2 on the rheological behavior of paper coating and the properties of coated paper was investigated.The results of rheological behavior experiment showed that at the same shear rate，the more amount of modified nanoTiO2，the higher the viscosity of paper coating.It was also proved that the dynamic elastic storage modulus and viscid loss modulus of paper coating containing modified nanoTiO2 were higher than those of paper coating containing unmodified nanoTiO2，while the phase angle was lower.Furthermore，the results of SEM and AFM showed that the better microscopic pore structure of coating surface could be built when modified nanoTiO2 was added into paper coating.In addition，with the increase of modified nanoTiO2 amount in the coated paper，the optical properties and printability of coated paper can be persistently improved.