Objective  To study changes in posterior corneal elevation after laser in situ keratomileusis （LASIK） and related factors. Methods  It was a retrospective case series study. One hundred and two eyes of 51 myopic patients undergoing LASIK were examined with a Pentacam preoperatively， and 1 month and 3 months postoperatively. Analysis included posterior corneal elevation of the corneal apex， temporal superior， temporal inferior， nasal superior and nasal inferior quadrants （7 predetermined points in each quadrant） in a 4mm area of the central cornea. Results  The changes in posterior corneal elevation in the corneal apex， temporal superior， temporal inferior， nasal superior and nasal inferior quadrants were -0.12±1.50 μm， 0.18±1.70 μm， -0.16±1.50 μm， 0.15±1.62 μm and 0.01±1.45μm， respectively， at 1 month， and were 0.58±1.49 μm， 0.42±1.85 μm， -0.50±1.99 μm， 0.59±1.67 μm and -0.36±1.70 μm， respectively， at 3 months. Between postoperative 1 month and 3 months， there was a significant difference in changes in the posterior elevation of the corneal apex， but there were no statistically significant differences in the 4 quadrants. At 1 month postoperatively， changes in the posterior corneal elevation in every area did not correlate with central corneal thickness （CCT）， residual bed thickness （RBT）， ablation depth （AD） or spherical equivalent （SE）. At 3 months postoperatively， there was a significant positive correlation between changes in posterior elevation in the corneal apex and SE， but there was no significant correlation between changes in posterior corneal elevation in 4 quadrants and CCT， RBT， AD， SE. Conclusion  LASIK surgery induces tiny changes in posterior corneal elevation in the central 4 mm area. Higher refractive errors may increase the trend of a forward shift of the posterior surface of the corneal apex.