The superfamily of the Eriophyoidea is a large and diverse group of mites, including a number of species with economic importance. The importance of these mites are because of the direct damage to their hosts, their ability to transmit plant pathogens especially plant viruses, and also their potential to use as biological agents for weed control. Despite their small body and low mobility, they can disperse passively through air currents, rain and especially, human practices, which increases their importance. Most identified species of the superfamily Eriophyoidea belong to the family Eriophyidae. Some of diagnostic characters of this family are as follows: Gnathosoma usually small in comparison to the body; when large, with chelicerae straight or slightly curved; pedipalps with terminal segments short and truncate and enclosing the short form oral stylet. Legs with usual segments and setae or with various reductions or modifications. Empodia usually entire; some are divided or modified. Opisthosoma with standard setae or with various reductions; setae h1 small or often absent. During the study of plant samples collected in Sari county, Mazandaran province, Iran, in summer 2017, eriophyoid mites were recovered by means of Lotfollahi (2013) modified washing method. The mites were slide mounted according to Baker et al. (1996). All morphological measurements were taken by means of a phase contrast microscope Olympus BX41 according to Amrine and Manson (1996) as modified by de Lillo et al. (2010). From identified species, six species belonging to four genera of the family Eriophyidae are introduced here which among them one species is new to world mite fauna and five species are new records to the fauna of Mazandaran province. The identified species are as follows: Aceria sp. nov. and Aceria granati (Canestrini & Massalongo, 1894) from Punica granatum L. (Punicaceae), A. cynodonis Wilson, 1959 from non-host plant species, Shevtchenkella juglandis (Keifer, 1951) from Juglans regia L. (Juglandaceae), Abacarus hystrix (Nalepa) from non-host plant species and Leipothrix pterisfolii lotfollahi & de Lillo, 2017 from Polypodium vulgare L. (Polypodiaceae).