Abstract: The present study investigated the effects of water soluble matter from oxidized soybean oil on the growth, morphology and structure of intestinal epithelial cells (in vitro) from Ctenopharyngodon idella. The water soluble matter was applied at different concentrations for various periods of time. The activity and survival of cells were significant reduced after 6h incubation with culture medium supplemented with water soluble matter in the concentration range of 111.06-888.48 g/L. Furthermore there was an associated decrease in the size of cell colonies as well as a change in cell morphology. When the water soluble matter from oxidized soybean oil reached the concentration of 444.24 g/L, the formation of fat droplets and vesicles in cells could be observed under transmission electron microscope, as well as swelling mitochondria in cells. During 3-9h incubation, LDH activity significantly increased; there was also significant change in GSH-PX, SOD activity and T-AOC. In conclusion, during 12 hours the dissociated IECs from Ctenopharyngodon idella could be damaged by the water soluble matter from oxidized soybean oil in the concentration range of 111.06-888.48 g/L. The damage occurs primarily in the manifestation of altered growth-inhibitory, morphology, and cell structure, probably involving the lipid peroxidation in cell membrane and the subsequent destruction in cell structure. The extent of damage is correlated with the concentration and incubation time. Overall, there was significant damage of water soluble matter from oxidized soybean oil on IECs in vitro.