The purposes of this research were : to study and to compare energy conservation behavior of Makham Sansern high school students, Chanthaburi Province. The data were analyzed by personal factor, age, class, knowledge and understanding of the energy conservation. The samples consisted of 217 students at Makham Sansern School. The data were gathered through a questionnaire and analyzed with statistical techniques, including percentage, mean, standard deviation, t-test. The results of this research identified : 1) energy conservation behavior of Makha