This review introduces the characteristics of electrical signals in higher plants and their corresponding physiological significance,and describes in detail the impact of environmental factors (e.g.light and temperature) on the electrical potential of the plants.Also,we evaluate the measurement techniques used for electrical signals in plants,including intracellular measurement,extracellular measurement,measurement of the ion channel based on the patch-clamp technique and on the non-invasive microelectrode vibrating probe technique.We also give a brief review of the applications of these methods for investigating electrical signals in plants.The ionic mechanism of electrical activity in plants is then discussed in terms of environmental response in higher plants,and this is used to provide a theoretical basis for quantitative description of the electrical signals in plants.A model for interpretation of the electrical signal mechanisms in higher plants is discussed,but further experiments are required for the verification of this model.(C) 2009 National Natural Science Foundation of China and Chinese Academy of Sciences.Published by Elsevier Limited and Science in China Press.All rights reserved.