The hysteretic effects which have been discovered and studied in the soil-plant-atmo-sphere continum are the moisture characteristics,the hydraulic conductivity characteristics and the rate of water flow in plant-water potential relationships.The actual phenoma of cosiderable hysteresis characterizing the hydraulic conductivity-capillary head relationships,and the less significant hydraulic conductivity-moisture content hysteresis,is proposed.The theories and predicting models of hysteretic effects are reviewed in this paper.The problems and new taskes are discussed at last.