AIM:To measure fundamental secretion of tears in young and middle-aged people with Han nationality in Xi'an, and the fundamental secretion of tears in the same samples after they inhabited in 4 300 meter region for 1mo, in order to provide the foundation for further research on prevention and interventions of dry eye in crowd from plain to high altitude region.

METHODS:The 43 normal volunteers with 86 eyes were conducted with the Schirmer test to hang the test paper at 1/3 eyelid margin. The length of stained test paper was measured after 5min. After 1mo the volunteers lived in high altitude region, the same test was conducted binocularly.

RESULTS:The length of stained test paper in young and middle-aged people with Han nationality was 14.21±3.32mm in Xi'an. And then significantly increased to 20.10±6.62mm after 1mo they lived in high altitudes region.

CONCLUSION:There is significant difference of fundamental secretion of tears between the people in Xi'an and those in other areas. Also there is significant difference of fundamental secretion of tears in people before and after living in Plateau.