Dielectric parameters and volume percent of extracellular fluid of apples which were pressed under certain pressures 12 hours using universal testing machine were respectively monitored by parallel polar plate method and stainless steel electrode. The results were as follows： with static pressure increase， relative dielectric constant and loss factor were increase. In a certain static pressure， with time prolonging， relative dielectric constant and loss factor were increase， and volume percent of extracellular fluid also was increase and was bigger with pressure increase. There were high correlation between the volume percent of extracellular fluid and dielectric parameters（r>0.9）， so the change of dielectric parameters could reflect the physiological change of apple. According to the changes of dielectric parameters during static pressure， the process of static pressure of apple was divided into three phases. They were rapid changes phase of dielectric parameter in t≤0.5h in which average rate of change was 28.19％， slow changes phase in 1h≤t≤3h in which average rate of change was 4.24％ and basically remained unchanged phase in 4h≤t≤12h in which average rate of change was 0.67％. The results show a new idea to simultaneously monitor physical and chemical quality and physiological state of fruits， and also provide a theoretical guidance for rapid evaluating the damage degree of fruit by the method of electrical characteristics.