Abstract: The purpose of this paper was to explore the regularity of the texture of fresh-cut potatoes with pressure and the mechanism of texture change. The effects of ultra high pressure(HPP,100~600 MPa,10 min)on the color,hardness,chewing degree,cell wall related enzyme activities and polysaccharide composition of fresh-cut potatoes were studied. The results showed that HPP inhibited the browning of fresh-cut potatoes at a pressure of ≥ 500 MPa,and the browning was severe at 300 MPa and the degree was higher than the blank. Compared with the traditional heat treatment,HPP could better maintain the hardness and chewing degree of fresh-cut potatoes. However,compared with the blank,the hardness of potatoes after HPP treatment decreased with various degrees,and the hardness decreased most at 300 MPa. And when the hardness reached 500 MPa,there was a rebound,and the chewing degree also had a rebound phenomenon under this pressure. HPP changed the cell wall-related enzyme activity and polysaccharide contents of potato to some extent. Pectin methylesterase(PME)activity was stable at pressure ≤ 500 MPa,while HPP inhibited polygalacturonase(PG)and endo β-glucanase(Cx)activity,increased β-glucosidase and exo-β-glucanase(C₁)activity at pressures of 100,500,and 600 MPa. Compared to the blank,the contents of cellulose(CEL),alkali soluble pectin(NSF)and chelating pectin(CSF)of fresh-cut potatoes after HPP treatment was significantly improved,and the CSF content was significantly(P<0.05)lower than the blank level at 300 MPa,and the water soluble pectin(WSF)contents decreased significantly(P<0.05)at 100,600 MPa,and there was no significant change under other pressures,while the hemicellulose(HC)contents of fresh-cut potatoes decreased significantly(P<0.05)after HPP treatment. Correlation analysis showed that the hardness and chewiness of potatoes after HPP treatment were significantly or positively significantly(P<0.05 or P<0.01)correlated with CSF,NSF and CEL,and had negatively significantly correlated with WSF contents,and had no significantly correlated with HC contents. The index had a greater impact on itstexture index. In summary,the composition and contents of polysaccharides in the cell wall after ultra high pressure treatment could affecte the texture of fresh-cut potatoes.