AIM:To evaluate and compare the influence of laser in situ keratomileusis(LASIK) and sub-Bowmans keratomileusis(SBK) on the elevation of posterior corneal surface in moderate to mild myopia. ·METHODS:Totally 108 patients with mild to moderate myopia were included. One eye in each patient was randomly selected to have LASIK(Group LASIK,n=108),and SBK was performed in the follow eye(Group SBK,n=108). Changes in the elevation of posterior corneal surface were measured with Pentacam system (Pentacam,OCULUS) preoperatively and 1 week,1,3,and 6 months postoperatively. ·RESULTS:After surgery,the acuity of vision in all eyes reached or exceeded that of preoperative. The posterior corneal surface in Group SBK displayed a mean elevation of 7.08±4.10μm,6.54±4.27μm,6.48±3.41μm,6.63±3.11μm and 6.59±3.23μm,in preoperative,1 week,1 month,3 months and 6 months postoperatively,respectively. In Group LASIK were 7.29±3.83μm,7.07±3.92μm,7.04±4.13μm,7.15±2.80μm,7.09±3.01μm respectively. None of the elevation of posterior corneal surface of Group LASIK or SBK was found to have a significant change after surgery. ·CONCLUSION:LASIK and SBK don’t affect the elevation of posterior corneal surface significantly.