The purpose of this research is to the effect of health behavior modification on the Overweight program of public health students, Roi – et university. This research is a participatory action research. Using a questionnaire developed by a researcher. The collegian in the fields Public health. Roi-et university has body mass index since the 23.00 - -25.00 kg/m2 all 15 people. Data collection were conducted 2 times ; before program and immediately after program. Sub – Didtrict Frequency, Percentage, Mean, Minimum, Maximum, standard Deviation. Inferential statistic and Paired Sample T – test used in this research.