With the advance of sequencing technology, the number of sequenced plant genomes has been rapidly increasing. However, understanding of the gene function in these sequenced genomes lags far behind; as a result, many coding plant sequences in public databases are annotated as proteins with domains of unknown function (DUF). Function of a protein family DUF810 in rice is not known. In this study, we analysed seven members of OsDU810 (OsDUF810.1-OsDUF810.7) family with three distinct motifs in rice Nipponbare. By phylogenetic analysis, OsDUF810 proteins fall into three major groups (I, II, III). Expression patterns of the seven corresponding OsDUF810 protein-encoding genes in 15 different rice tissues vary. Under drought, salt, cold and heat stress conditions and ABA treatment, the expression of OsDUF810.7 significantly increases. Overexpression of this protein in E. coli lead to a significant enhancement of catalase (CAT) and peroxidase (POD) activities, and improved bacterial resistance to salt and drought.