The purposes of this thesis were to study the level of knowledge and awareness of the police cadets concerning environmental problems, the relation between knowledge and awareness concerning environmental problems and to study factors influencing the knowledge and awareness of the police cadets concerning environmental problems. Data were collected by submitting a questionnaire to police cadets from the Royal Thai Police Cadet Academy. There were 596 cadets who responded to the questionnaire. Their responses were analyzed with a variety of statistical techniques i.e. percentage, mean, standard deviation, one-way analysis of variance, Pearson - Product - Moment correlation and stepwise multiple regression analysis. The police cadets knowledge concerning environmental problems (forest and air pollution) is at a medium level. It was also found that the average score was 19.49, or 68.87 percent. From the analysis of the relationship between police cadets characteristics and communication behavior and knowledge concerning environmental problems, it was found that education level, secondary school, place of residence, membership in groups, experience in environmental problems and mass media communication behavior were factors significantly correlated with knowledge concerning environmental problems. The factors affecting knowledge concerning environmental problems were membership in groups, place of residence, education level and age. 2. The police cadets awareness concerning environmental problems (forest and air pollution) was at a high level and the average score was 146.79, or 81.11 percent. The analysis of the relationship between police cadets characteristics and communication behavior and awareness concerning environmental problems was found that education level, secondary school, place of residence, mothers occupation, membership in groups, experience in environmental problems and mass media communication behavior were factors significantly correlated with awareness concerning environmental problems. The factors affecting awareness concerning environmental problems were place of residence, membership in groups, education level and experience in environmental problems. 3. the relationship between knowledge and awareness of the police cadets concerning environmental problems on forest and air pollution was found to be significantly positive. From the research findings, the recommendations are to encourage the police cadets to participate in environmental activities and to acquire additional knowledge through the mass communication media.