Creator's Description: The collection of wild edible fungi has a long-standing history in Tibet. Today, a wide variety of mushrooms is collected to supplement rural income. Because of the lucrative economic return, rural Tibetans have increased their gathering activities substantially. Matsutake (Tricholoma matsutake) is the most important culinary mushroom in Nyingtri (Nying khri) and southern Chamdo (Chab mdo) Prefectures. This article will present data on its distribution in the Tibet Autonomous Region, production level, and harvest value at the county level as well as typical seasonal activity typified by two collectors. The trade of dbyar rtswa dgun 'bu, as Tibetans know caterpillar fungus (Cordyceps sinensis), has developed into the main source of income in rural Tibet. It accounts for 40 percent of rural cash income and is spurring a globally unique commodification of fungi in the TAR. In late 2007 the value of the best-quality dbyar rtswa dgun 'bu in Lha sa traded for around CN ¥80,000 (nearly US $12,000) per pound. The value of the fifty-ton annual harvest of Cordyceps surpassed the value of the industry and mining sector in 2004. Most county agencies have established a permit system and require collectors to obtain licenses. The ever-growing economic importance of these fungi raises concerns regarding sustainability of current harvest levels. There are scientific studies regarding matsutake that conclude that when using appropriate harvesting techniques sustainability should be guaranteed. However, the situation regarding Cordyceps sinensis is not clear. Although current harvest figures are at historically unmatched levels, areas in which dbyar rtswa dgun 'bu has been collected for centuries still maintain good resources.