The origin of the word of "Manna" has not been satisfactorily explained. Manna is a kind of sugar material produced on young plant organs during some insect activities or reaction of plant mechanical factors or temperature out of plant tissues. These material has high medicinal, nutritional and commercial values are accounted as important by-product of Forests and Rangelands in some areas produces and uses. Some plant manna that which has been investigated in national projects titled.Investigation and identification of manna sources and production mechanism in Iran in Tehran and other parts of Iran in the period 1993-2000 which are discussed in this paper include:1- Gazangabin (Astragal Manna):It is a manna exudes as white spiral, segmented fibes by Cyamophila dicora Log. (Horn.: Psylidae) nymphs.2- Shir-Khesht (Cotoneaster Manna): Occur as sweet, small, grayish-white granules during july and early August on Cotoneaster branches attacked by Scolytus rogulosus Mull. In few days the material sloughs off, which is then collected and mixed with what flour used as laxative. 3- Bid-Khesht (Willow Manna):A white, sweet fairly hard, manna with delightful smell. This compound is produced on the leaves and young branches of some willow by Tuberolachnus salignus (Gmelin), an aphid of Lachnidae family.4- Shekar-Tighal (Trehala Manna): Shekar-tighal is a manna produced on young shoots or leaves of Echinops spp. By the salivary glands of weevils (Larinus spp.) The compound dries and hardens fast following exudation. Several species of weevils of the genus Larinus ave so far been collected and identified as producing agents in Tehran, Fars, Lorestan, Esfahan, Khorassan and East-Azarbaijan provinces, These include: Larinus onopordi L., L. o. var. maculatus Fahr. 1. arabicus Cap., 1. Mellificus and 1. vulpes Olive. 5- Gaz-e-Alafi (Oak manna): Gaz-e-Alafi is a valuable by product of western oak forests specially in northern parts of Zagross. The manna is produces on the leaves surfaces and young branches of two oak species (Quercus infectoria Oliv. And Q. brantii Oliv.) by nymphs and adults activities of two aphids (Tuberculoides anualatus Harting and The laxes suberi DeL). The material then is sticken as sugar crystallized and used. Production and utilization time of this material is on late spring and sometimes on fillst autumn. Distribution of host plants and aphids are in West-Azarbaijan, Kordestan, Kermanshah and Lorestan provinces, but producer aphids in West-Azarbaijan, Kordestan and Lorestan provinces are able to produce manna.6- Gaz-e-Shahdad (Tamarisk Manna) This sweet yellowish-white compound is produced by two species of insects such as; (Euscelis sp. Family Cicadelidae order Homoptera and Tuponia subaltera Drop. Family miridae order Heteroptera) on young branches of Tamarix aphylla.7- Tarangabin (Camel's thorn Manna): Camel's thorn Manna is a sugar made compound produced by Poophilus nebulosus Family Cercopidae, order Homoptera as a tiny white granules on the end part of Camel's thorn (alhagi camelorum).