Objective: To understand the mosquito infestation status in schools in Jing an District of Shanghai from 2019 to 2025, so as to provide a basis for mosquito control work in schools. Methods: Four schools of each school type (colleges and secondary specialized schools, primary and secondary schools, nurseries and kindergartens) were respectively selected from Jing an District as the survey sites by combination of stratified sampling and convenience sampling. Mosquito breeding sites surveys (including small stagnant water and medium and large static water) and adult mosquito monitoring were carried out in schools every August, from 2019 to 2025. The breeding sites surveys were investigated by visual inspection and spoon trapping methods, and the adult mosquito monitoring was investigated by the human baited trapping. Chi square test was used for inter group comparison. Results: A total of 970 small stagnant water were surveyed from 2019 to 2025, with the positive rate of 17.01% for mosquito breeding. The highest positive rate was in colleges and secondary specialized schools (25.07%). The top three positive breeding sites for mosquito were unused containers(27.46%), waste tires (16.67%), and bonsai and aquatic plants (16.52%). There were statistically significant differences in the positive rates for mosquito breeding among different years, school types and waterlogging types ( χ 2=122.70, 28.48 , 24.80, all P <0.01). A total of 640 medium and large static water were surveyed, and the positive rate for mosquito breeding was 7.34%. There was a statistically significant difference for the positive rate among different years ( χ 2= 50.23 , P <0.01). The highest positive rate for mosquito breeding was in colleges and secondary specialized schools (9.63%), and there was no statistically significant difference for the positive rate among different school types ( χ 2=4.41, P =0.11). From 2019 to 2025, a total of 390 mosquitoes were captured in the time period from 16:30 to 17:00, all of which were Aedes albopictus; the adult mosquito density in colleges and secondary specialized schools was the highest, being 2.38 mosquitoes/(0.5 h ·person). A total of 210 mosquitoes were captured in the time period from 19:00 to 19:30 during 2019-2025, among which Aedes albopictus accounted for 74.76% and Culex pipiens pallens accounted for 25.24%. The adult mosquito density in colleges and secondary specialized schools was the highest, being 1.15 mosquitoes/(0.5 h ·person). In colleges and secondary specialized schools, the area with the largest number of captured mosquitoes was around the teaching buildings and libraries(44.78%). In primary and secondary schools, as well as nurseries and kindergartens, the area with the largest number of captured mosquitoes was around the school gates and playgrounds( 49.44% , 53.60%), the difference in mosquito distribution in different regions among different types of schools was statistically significant ( χ 2=111.39, P <0.01). Conclusions The mosquito density in Jing an District schools is generally higher during summer. It is recommended that the school strengthen the management of mosquito breeding sites and the control of adult mosquitoes before the start of autumn semester, so as to prevent insect infestation of mosquitoes.