The purpose of this study was to study and compare spending behavior of undergraduate of Rajamangala University of Technology Phra Nakhon in 4 aspects : the food expense transportation expense health care expense and entertainment expense. The undergraduates were classified by gender academic years faculties income income source extra income and extra income source. The samples in this research were 432 undergraduates. The study participates selected by stratified random sampling. The 48 item questionnaires of rating scales was used as the research instrument. Percentage mean. standard deviation. t -test for independent sample F -test and LSD analysis were statistical method to analyze data. The results were as follows: 1. The undergraduates Spending Behavior all aspects were in moderate levels that the food expense was the highest health care expense and transportation expense was the lowest. 2. There was Significant difference for undergraduates spending behavior in health care expense entertainment expense and all aspects at the 0.05 level among students in different gender and academic years. 3. There was significant difference for undergraduates spending behavior in food expense health care expense entertainment expense and all aspects at the 0.05 level among students in different faculty. 4. There was Significant difference for undergraduates spending behavior in food expense and all aspects at the 0.05 level am<;mg students in different income and extra income. There was significant difference for undergraduates spending behavior in food expense transportation expense entertainment expense and all aspects at the 0.05 level among students in different income and extra income.