We investigated the effect of low-dose, long-term benzo(a)pyrene exposure on the miRNA expression profile in lung tissue of mice, and the potential mechanism of miRNAs in the benzo(a)pyreneinduced damage to health. Subject mice were treated with $5{mu}g/kg$ benzo(a)pyrene twice a week for 8 weeks by intragastrical administration, while control mice were treated with the same volume of olive oil solvent. All mice were then fed for another 8 weeks without exposure to benzo(a)pyrene, after which total RNA was isolated from lung tissue. miRNA expression profiles were generated by $SOLiD^{TM}3$ high-throughput sequencing and the signaling pathways represented were analyzed by DIANA-mirPath. A total of 74 miRNAs were dysregulated in mice lung tissues exposed to benzo(a)pyrene. Signaling pathways regulated by benzo(a)pyrene exposure included those involved in the environmental information process and human tumorigenesis. We conclude that low-dose, long-term benzo(a)pyrene exposure alters specific miRNA expression profiles.