Magnetic one-component toner for developing electrostatic latent image and method for forming image

A magnetic one-component toner for developing an electrostatic latent image for use in a magnetic one-component jumping development system, wherein the photo-sensitizer thereof is a-Si photo-sensitizer having a film thickness of 30 mum or less, a carrier for a developing agent has an Rz of 2.0 to 6.0 mum and the means for removing a toner from the surface of the above photo-sensitizer is a cleaning blade, and wherein said toner contains a titanium oxide added as an external additive, and the titanium oxide has a liberation percentage in the range of 10 to 22 % and contains a low resistance titanium oxide having a volume specific resistance value in the range of 100 to 107 ohm.cm and a high resistance titanium oxide having a volume specific resistance value in the range of 108 to 1013 ohm.cm in a mass ratio of the low resistance titanium oxide : high resistance titanium oxide = 1.3 : 1 to 4 : 1.