Objective To evaluate the distribution characteristics of the asphericity （Q-value） of the corneal surfaces in a Chinese population who were candidates for excimer laser surgery； to provide some theoretical bases for clinical diagnosis and treatment. Methods This was a perspective study. Using the Pentacam HR measuring and analyzing system based on Scheimpflug photography， the right eyes of 75 Chinese myopes were evaluated for excimer laser surgery. Patients were divided into a low corneal astigmatism （<+1.00 D） group and a medium-high corneal astigmatism （≥+1.00 D） group according to the anterior corneal surface astigmatism. The analysis was based on the distribution characteristics of the mean Q-values of both the anterior and posterior corneal surfaces and the distribution characteristics of the Q-value at different angles （20°， 25° and 30°） and along different semi-meridians （superior， inferior， nasal and temporal）. Single factor analysis of variance was used to determine if there was a difference among Q-values within a particular group. The differences between the two groups were analyzed by an independent samples t-test. Results The mean Q-values of the 30° angle in Chinese myopes evaluated for excimer laser surgery were -0.17±0.09 and -0.02±0.16 on the anterior and posterior corneal surfaces， respectively. The mean Q-values of the anterior corneal surface at different angles were negative and there was no statistically significant difference between the low corneal astigmatism group and medium-high corneal astigmatism group. There was a significant difference between the Q-values of the 2 groups at different angles （F=6.340， 9.963， P＜0.01）， and in both groups Q20 was significantly larger than Q30 and Q25 （P＜0.05） but there was no statistically significant difference between Q30 and Q25. The mean Q-values of the posterior corneal surface were positive at the 20° and 25° angles and approached zero at the 30° angle. Comparisons between the 3 angles showed statistically significant differences （F=54.614， P＜0.01）. The comparisons showed that Q30<Q25<Q20. All mean Q-values along different semi-meridians of the anterior corneal surface were negative and there was no statistically significant difference between the 2 groups. There was a significant difference between Q-values along different semi-meridians in the 2 groups （F=19.262， 31.935， P＜0.01）. In the low corneal astigmatism group， QN30 was significantly smaller than QT30， QS30 and QI30 （P＜0.05） but there was no statistically significant difference between QT30， QS30 and QI30 （P＞0.05）. In the medium-high corneal astigmatism group， QT30 was significantly bigger than QN30 （P＜0.05） but there was no statistically significant difference between QS30 and QI30. In addition， QN30 and QT30 were significantly smaller than QS30 and QI30 （P＜0.05）. The Q-values of the posterior surface were positive along the inferior semi-meridian， negative along the nasal and temporal semi-meridians， and approached zero along the superior semi-meridian. There was also a significant difference between Q-values along different semi-meridians on the posterior surface（F=31.750， P＜0.01）. There were statistically significant differences between QT30 and QN30 （P＜0.05） and QI30 and QS30 （P＜0.05）. Comparisons showed that QT30>QN30 and QI30>QS30， but there was no statistically significant difference between QT30 and QS30. Conclusion The curvature along the anterior corneal surface becomes flatter from the center to the periphery， while it becomes steeper from the center to the periphery at the posterior corneal surface. The rate of the flattening of the anterior corneal surface increased as the range of the angle increased， while the rate decreased as the posterior corneal surface decreased. All the shapes on the anterior surface along different semi-meridians were long ovals. Corneal astigmatism does not affect corneal shape. The shapes of the posterior surface along the superior and inferior semi-meridians were short ovals， but were long ovals along the nasal and temporal semi-meridians.