PURPOSE: To prevent offset phenomenon and filming of a toner by adding an oxidized type polyolefin to a monomer and polymerizing it.

CONSTITUTION: A polymer can be polarized and enhanced in compatibility with a colorant and prevented both from offset phenomenon and filming by adding an oxidized type polyolefin to a monomer and polymerizing it. As the monomer of a toner resin, styrene, methyl acrylate, vinyl hexyl ketone, etc. are usable. The oxidized type polyolefin can be obtained by polymerizing unsatd. carboxylic acid with polyolefin by grafting or using radiation, etc. and it is added by 2W 15pts.wt. per 100pts.wt. monomer, and preferably having an acid value of ≥1. Benzoyl peroxide, lauryl peroxide, etc. are usable for a polymn. initiator.