Motivated by the huge potential for two-dimensional materials in gas sensors, the adsorption behavior of gas molecules on the surface of penta-BP5 is investigated by first principles calculations. Results show that CO and CO2 have slight influence on the electronic property of penta-BP5 and the charge transfers are small, revealing that penta-BP5 is not suitable for detecting these two gases. However, penta-BP5 is sensitive to CH2O, SO2, O-2 and NO because that considerable adsorption energies and charge transfers can be found in the adsorption systems, indicating that penta-BP5 could be a potential sensing material for detecting these gases. (C) 2018 Elsevier B.V. All rights reserved.