Objective: To analyze the quality of the first permanent molars pit and fissure sealant for school-aged children in Xi'an from 2010 to 2018, and to provide a reference for preventing dental caries. Methods: A total of 5 871 children were selected from different regions from 2010 to 2018 by cluster random sampling method for the quality inspection of pit and fissure sealant. Results: The quality of pit and fissure sealant has been improved by year in Xi'an ( χ 2=1 326.39, P <0.01). The rate of intact sealant was 92.57% in 2018. The quality of project and reservation rate in rural areas(64.23%, 76.83%) were worse than those in urban (84.17%, 90.80%) and suburban areas(84.21%, 91.88%)( χ 2=310.58, 296.52, P <0.01); The quality of pit and fissure sealant was highest in tertiary hospitals(87.28%, 91.07%), followed by private hospitals(84.60%, 91.43%), primary hospitals(84.42%, 92.02%), secondary hospitals(72.79%, 84.45%)( P <0.01). Conclusion The quality of pit and fissure sealant in Xi'an reached the national requirement, but there is obvious gap between town and country, the quality of project varied substantially across medical institutions .Training and supervision should be strengthened in the future work.