Estimation of hydraulic resistances of soil-plant climate continuum (SPAC) is important both for describing water movement in the continuum and for adopting practical water-saving measures in agriculture to find the solutions to seasonal drought in the area of Red Soil of China. The diurnal variation of stomatal resistance of crops in dry season was observed and its relation to transpiration rate and water potentials of crop leaf and soil in different farming systems was also studied. Results indicated that stomatal resistance and transpiration rate were different for each crop in different farming systems. Stomatal resistance was related to soil water potentials within the soil layers of 70cm. The hydraulic resistances of the leaf-air interface in SPACs ranged from 10⁹ to 10¹⁰ S, which was 1000 times higher than those of crop body. The resistance of crop body was 100 times as much as that within the soil layer of 70cm. In dry season, soil resistance increased with the depletion of soil water. Resistance of crop body fell in the order: soybean>peanut>corn>sweet potato, which experienced dramatically diurnal variation except that of sweet potato. Resistance of crop also varied with cropping systems.