Sustainable use of rangelands requires information on vegetation cover and its changes through time, condition trend and the effect of climate as well as management practices. The main objective of this research was showing variation of vegetation parameters, i.e. vegetation cover, soil surface cover, production and density, in the long term in three provinces of Iran, Markazi, Isfahan and Yazd. Efficiency of satellite data for estimation of vegetation parameters and suggestion of a system for vegetation cover monitoring were other goals of the study. All selected provinces were equipped with one site locating in the key area of the main vegetation communities. Data in arid and semi arid areas were collected along four 400 or six 200 meter transects using 60 two or one square meter quadrates.  Correlations between satellite data and ground truth data were investigated. Primary results shows that range ecosystems in arid regions of all three provinces have fragile conditions. Rangelands in these provinces generally are characterized with low vegetation cover, small production and poor range conditions. Desirable species were absent in vegetation composition in its place moderate or low desirable species are abundance. Biological balance has been lost because of sever grazing.  Integration of five years field and satellite data, the time course of the study, indicates that range assessment in wide areas, with assistant of digital data is possible. Also application of GPS and GIS can facilitate using correctly satellite data in a national monitoring system.