Nanomaterials or nanoparticles (NPs) are nano-size particles with a (1-100) nm dimension, they show unique properties such as magnetic, electronic, optical, and activating effects. That is why NPs have many applications. Titanium dioxide (TiO2) or Titania based nanoparticals are commonly used NPsdue to their medical and industrial applications. TiO2NPs are used in photodynamic therapy (SDT) and drug delivery due to their non-toxicity. In this review paper we will show some of the types, synthesis methods, and applications of nano-TiO2.