Contents mi RNAs are small non-coding regulatory RNAs that play key roles in diverse biological processes. In this study, we used the Solexa sequencing technique to profile mi RNAs in breeder cock testes to illustrate their functions. A total of 663 co-expressed mi RNAs and 3,180 co-expressed pi RNAs were detected in three libraries. Based on Mir-X™ mi RNA qRT- PCR, three mi RNAs representing low, medium and high expression levels according to the sequencing results were selected randomly to validate the mi RNAs' expression profiles. Results suggested that the mi RNA expression profiles data could represent actual mi RNA expression levels. Moreover, target genes prediction of the co-expressed mi RNAs and further Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses were performed, which revealed that some candidate mi RNAs were involved in the regulation of the spermatogenesis process, spermatozoa function and testicular metabolism. In conclusion, we provided a useful resource for further elucidation of the mi RNAs' regulatory role in spermatogenesis, contributing to a preliminary database for functional and molecular mechanistic studies in testicular metabolism, spermatogenesis and other testes functions. [ABSTRACT FROM AUTHOR]