In actuality, as most of harmful businesses running at school environment hygiene purification zones are stationeries with game rooms, comic book stores, PC rooms, etc., which are highly accessible to students, they become serious problems in school environment. The present study conducted a survey of violation cases at school environment sanitation and purification zones around 21 elementary schools in Seoul. The objectives of this study are, first, to investigate harmful environment around schools regulated by the School Health Act, and second, to suggest plans to improve harmful environment around schools. According to the results of our survey, illegal acts and facilities observed at school environment sanitation and purification zones are as follows. Amusement pubs/room saloons occupied 52.5%, singing rooms 15.4%, game rooms 15.1%, billiard clubs 4.3%, gambling houses 4.3%, hotels/motels/inns 3.6%, cartoon shops 2.6%, video rooms 1.0%, LPG storages 0.7%, and infectious disease hospitals/detention hospitals/detention facilities 0.7%. As it is required to make continuous and systematic surveys and researches on the environmental hygiene around schools, we need to manage school environment efficiently through cooperation among the government, education offices and individual schools.