Productivity, illustrates the relationship between the quantity of produced goods and services, output, and the quantity of labor, capital, land, energy, and other resources that produced it, the input, is a key element in analyzing an economy, for it illustrates both the efficiency of industry and the wealth-generating capability of the economy. However, this paper computes key industries to promote overall labor productivity in Iran by xiaoming, 1998 method. In this study, we use the Input-Output tables of Iran for the years1984, 1988, 1993, 1999 and 2005. We found that paper industry and water, electricity and Gas and financial sectors are key sectors or productivity incentives sectors in Iranian economy.