To understand the complex physiological process underlying pig testis development and spermatogenesis, this study aims to characterize the change in miRNA and mRNA profiles at four developmental stages of embryonic and postnatal testes, including 60 dpc (days post coitus, E60), 90 dpc (E90), 30-day-old (D30) and 180-day-old (D180). A total of 304 mature, 50 novel miRNAs, and 8343 differentially-expressed genes were identified. 93 (48 up and 45 down), 104 (49 up and 55 down), 122 (49 up and 73 down) differentially-expressed miRNAs, as well as 1007 (646 up and 361 down), 1929 (911 up and 1018 do...