AIM:To investigate the relationship between the change of corneal biomechanical parameters and corneal topography after laser in situ keratomileusis (LASIK). ·METHODS:Sixty-nine patients 136 eyes after LASIK surgery were included in this study. Ocular response analyszer (ORA) was used to measure corneal hysteresis (CH) and corneal resistance factor (CRF); Pentacam were used to measure the corneal topography before and one month after LASIK. The changes of ΔCH and ΔCRF,central corneal thickness (ΔCCT),ΔCCT2mm,ΔCCT4mm,ΔCCT6mm,corneal volume (ΔCV),radius of curvature of the anterior and posterior corneal surface (ΔRa and ΔRp) were calculated. Pearson correlation analysis was applied to study the relationship between ΔCH and ΔCRF with corneal topography index. ·RESULTS:The CH and CRF were decreased significantly from 9.99±1.38mmHg and 9.96±1.30mmHg to 7.90±1.16mmHg and 6.49±1.28mmHg (P<0.05). No statistically significantly difference was found in both ΔCH and ΔCRF with ΔRp and ΔCCT6mm(P>0.05). The positive correlation between ΔCH and ΔCCT(r:0.513),ΔCCT2mm(r:0.397),ΔCCT4mm(r:0.329) and ΔCV(r:0.314) were significant(P<0.005). The positive correlation between ΔCRF and ΔCCT(r:0.616),ΔCCT2mm(r:0.504),ΔCCT4mm(r:0.484) and ΔCV(r:0.466) were significant(P<0.01). The negative correlation between ΔCRF and ΔRa(r:-0.374) was significant(P<0.01). ·CONCLUSION:Changes in CH and CRF after LASIK suggest that alteration in corneal biomechanics is correlated with CCT and CV. The CRF parameter may be more useful than the CH parameter in assessing biomechanical changes resulting from LASIK.