Field surveys of species in the family Muridae and their food resources were conducted in Cat Tien National Park, Vietnam in March 2011 and March and September 2012. Species were identified by DNA barcoding using polymorphic mitochondrial DNA sequences (COI, Cyt b, and D-loop) and external morphology. A total of four species, Maxomys surifer, Niviventer fulvescens, N. bukit, and Rattus sp. were identified. In order to identify which food resources were utilized by these species in the study area, total DNA was extracted from the gastric contents of the collected individuals. Sequence fragments of the chloroplast rbcL and the mitochondrial COI genes were amplified by PCR from the gastric contents and used to identify plant and animal food resources, respectively. We detected 34 plant families and seven animal orders by the homology search using the BLAST algorithm.