A photo-curing polysiloxane composition includes a polysiloxane, an o-naphthoquinonediazidesulfonate compound, and a solvent. The polysiloxane contains 25 wt % to 60 wt % of a polysiloxane fraction having a molecular weight ranging from 10,000 to 80,000 based on a total weight of the polysiloxane when calculated from an integral molecular weight distribution curve obtained by plotting cumulative weight percentage versus molecular weight falling within a range between 400 and 100,000 measured by gel permeation chromatography. The amount of oligomers in the polysiloxane having a molecular weight less than 800 is from 0 wt % to 10 wt % based on a total weight of the photo-curing polysiloxane composition. A protective film formed from the photo-curing polysiloxane composition and an element containing the protective film are also disclosed.