Abstract: There are many kinds of drought indicators expressing drought stress in field scale. This paper briefly reviewed these indicators and their data availability, pointed out the advantages and shortcomings. The integrated drought stress indicator, CWSI, its calculating procedure and application in agricultural practices were mainly described. The established relations of CWSI-ETa/ET_(p) and CWSI-T_(a)/T_(p) based on the field water cycle is the most integrated method,which directly considered the integrated effect of soil, plant, and atmosphere, and also closely connected with crop growth. It has both strict theoretical basis and good data availabilitythat can be obtained from the routine meteorological observations, and thus should become the first choice in assessing effect of drought stress on crop yield in field scale.

Key words: Drought indicator, Drought indicator, Field scale, CWSI, Canopy temperature, Penman-Monteith model