a biodegradable or hydrolyzable toner for electrophotography , which permits the easy reclaiming and recycling of used copying paper , permits the easy deinking by an existing deinking system , can decrease environmental pollution caused by a toner waste , and has excellent toner properties owing to the uniform dispersion of additives , the toner containing , as a binder resin , a lactic acid - based resin of the formula , h ---- co --]. sub . n -- or wherein r is an alkali metal or an alkaline earth metal , and n is an integer of 10 to 20 , 000 .