We have investigated the application of polymerized toner to one-component non-magnetic development system, especially focused on the relationship between toner layer states and its particle shape and charge. The spherical shaped polymerized toner, produced by our single-stage-dispersion system, is required less force and rotation time of development roller to build stable toner layer comparing with an irregular shaped conventional toner. Polymerized toner used the charge controlling agent having functional groups such as SO₂NH₂ or NO₂ on typical azo-iron complex dye, can be sufficiently charged for development. Print qualities with these toners are satisfactory, as the toner layer built on a development roller is uniform, thin and tight.