AIM:To observe the clinical efficacy of Laser-assisted subepithelial keratomileusis(LASEK) treatment of moderate and high myopia.·METHODS:All 85 eyes of 46 patients with moderate to extremely high myopia were treated with LASEK and followed up for more than 6 months.These eyes were divided into Group I(-3.25～-6.00)D,Group II(-6.25～-10.00)D and Group III (-10.25～-12.9) D by spherical equivalent refraction.The main outcome measures were postopera-tive uncorrected visual acuity(UCVA),best spectacle-corrected visual acuity(BSCVA),manifest refraction,tonometry and haze.·RESULTS:At 6 month postoperatively,the UCVA was 1.0 or better in 100%,78%,75% of eyes each group,respectively,and 0.5 or better in 100%,96%,88%;68.4%,58.0%,and 43.7%,respectively,were within ±1.00D of emmetropia;No eyes lost more than two lines of BSCVA;The mean spherical equivalent was (-0.38±0.66)D、(-0.77±1.25)D、(-1.25±1.97)D,respectively.At 6 month posto-peratively,eyes in group II and III developed varying degrees of haze and haze of all patients was under control at 2 grade below.·CONCLUSION:LASEK appeared to be an effective and safe treatment for correction of moderate to extremely high myopia.Haze and myopic regression were the main complications of LASEK for the treatment of high and extremely high myopia.Reducing the incidence of haze may have control on the rate of myopic regression.