Abstract: Lubrication experiments of medium plates in hot rolling were carried out under different lubrication conditions to analyze the relationship between rolling force and compressibility and study the effect of lubrication on the slab surface quality. The influence of lubrication conditions on the structural transformation in the steel plates was also discussed in combination with the continuous cooling transformation curve of the experimental steel. It is shown that lubrication oil with high concentration can reduce more rolling force than that with low concentration, and this effect is more obvious in rough rolling than finish rolling. Lubrication in hot rolling improves the slab surface quality, decreases the slab surface roughness, promotes ferrite transformation, reduces zonal structure near the slab sur-face, and makes the deformation uniform and the probability of surface defects lower.