Objection: For better understanding of texture change of high pressure processed fruits and vegetables during pressure come-up time and its extended storage. Method： Hardness of carrot subjected to high pressure（100-600 MPa， 0-2 min） was evaluated， and two-week storage was carried out to record hardness change. Potential mechanism of hardness softening was analyzed based on cell membrane integrity， cellular microstructure as well as enzymatic degradation and fractions conversion of pectin material. Result： Results showed that pressurization more than 200 MPa caused significant hardness loss（P<0.05）， with only 37.7% hardness remained after 300 MPa treatment. There was no dramatic hardness change during 0-2 min pressure holding time， neither in the process of storage. Relative electrolyte leakage increased with pressure rise， which indicates increase in membrane permeability. Microstructure observation by transmission electron microscopy showed that high pressure processing led to cell deformation. Membrane rupture， cells collapsed were observed at 400， 600 MPa respectively. With the effect of high pressure processing， cell separation and cell wall degradation during the period of two-week storage at 4 ℃ were promoted. Pectin methylesterase and polygalacturonase remained considerable activities. Content of water soluble pectin decreased significantly（P<0.05)， resulting conversion to chelator， sodium carbonate soluble pectin. Conclusion: The main cause of softening of carrot was mechanical damage of cell membrane brought by high pressure processing， but conversion of pectin fractions benefited hardness retention within storage duration.