Objective To analyze the changes of the parameters of anterior segment of eyes after femtosecond laser LASIK. Methods In this prospective clinic study, 50 eyes of 25 patients who underwent femtosecond laser laser in situ keratomileusis (LASIK) were included. The corneal endothelium density, anterior chamber depth, anterior chamber angle width, posterior corneal surface height (4 mm diameter), distance between pupil center and corneal vertex, pupil diameter under light and dark environment were compared before and 6 months or more after surgery. Distance between pupil center and corneal vertex using absolute value. Data were analyzed using paired t test. Results After surgery, corneal endothelium density (2 829.7±227.2 cells/mm2 vs. 2 716.4±255.2 cells/mm2), anterior chamber depth(3.18±0.19 mm vs. 3.08±0.21 mm), anterior chamber angle width (39.39°±3.90°, 37.92°±3.76°) decreased (t=3.077, 11.079, 5.241, P＜0.01). The differences of posterior corneal surface height (4 mm diameter), pupil diameter under light and dark environment before and after surgery were insignificant. The distance between pupil center and corneal vertex on X axis increased (0.11±0.10 mm vs. 0.14±0.12 mm, t=-3.318, P＜0.01). The distance between pupil center and corneal vertex on Y axis increase(0.11±0.08 mm vs. 0.15±0.11 mm, t=-4.157, P＜0.01). Conclusion The parameters of anterior segment of eyes after femtosecond laser LASIK changed obviously, especially for the distance between pupil center and corneal vertex. Maybe this change is important in guiding the following surgery.