AIM:To compare higher order aberrations(HOA)and their changes after surface and stromal ablation surgeries.METHODS:This prospective study included 200 eyes of 100 patients who sought for refractive surgery;50 patients(100 eyes)received laser in situ keratomileusis(LASIK)and 50 patients(100 eyes)received advanced surface ablation(ASA).Spherical equivalent(SE)of LASIK group ranged from-1.25 to-9.25(-5.75±1.74)D,SE of ASA group-2~-9.25(-5.42±1.81)D.Uncorrected visual acuity(UCVA),best spectacle-corrected visual acuity(BSCVA),spherical and cylindrical diopter,SE,and wavefront aberrations were recorded pre-ablation,1 month,3 and 6 months post-ablation.RESULTS:Changes of C7,C12,RMS3-6 and RMSh positively correlated with changes of spherical,cylindrical diopter and SE.C7,RMS3,RMS6 and RMSh of ASA group were smaller compared with LASIK group at 1st month post-operation;C7 and C14 of ASA were also smaller at 3rd month post-operation,while C12 of LASIK was smaller;only C14 of ASA was smaller than LASIK at 6th month post-operation.Compared with LASIK group,changes of RMS3,RMS5,RMS6 and RMSh in ASA group were smaller at 1st month post-operation;changes of RMS6 in ASA was smaller at 3 months post-operation;changes of RMS3,RMS6 and RMSh in ASA were smaller at 6th month post-operation.CONCLUSION:Increase of HOA positively correlate with changes of SE and spherical diopter.Both HOA and its increase in ASA group are smaller when compare with LASIK group,which maintain until 6 months post-operation.