Eleocharis vivipara is an amphibious sedge that displays C4 traits under terrestrial environments and C3 traits in submerged environments. This plant is thus potentially advantageous for screening genes indispensable to the development of C4 photosynthesis. In this study, we performed de novo transcriptome analysis of E. vivipara using its terrestrial-and submerged-type plants. By next-generation sequencing (NGS), approximately 90 and 89 million reads were yielded for the terrestrial and submerged types, respectively, and were assembled into 27,249 unigenes. Of these de novo consensus sequences, 94.5% showed similarities to database-registered sequences, and 69.4% were assigned with Gene Ontology terms. Our de novo assembled sequence data should provide a foundation for genetic analysis of the C4 photosynthetic system.