Some physiological indices of common bean were measured under self-designed devices for control of water supply tension as negative values. The result showed that soil water content、the quantity of consuming water、dry weight of root and shoot declined gradually with the increase in water supply tension; Plant height、leaf numbers、fresh and dry weight of fruit all went up first and then came down with the maximum under 20hPa; when the water supply tension was between 60hPa and 90hPa, leaf numbers、fresh and dry weight of fruit dropped slowly; R/S minished first, then rose, and decreased again, with the minimum value under 30hPa and the maximum value under 70hPa; The net photosynthetic rate(Pn) and transpiration rate(Tr) rose at the beginning, and then went down with peak value of Pn under 20hPa and Tr under 30hPa;The content of chlorophyll a(Chl a)、b(Chl b) and carotenoid(Car) in leaves increased first and then decreased with peak value under 30hPa.
