In the cold spraying process, particle velocity and temperature are commonly regarded as the key factors that influence the deposition efficiency and properties of the coating. In this study, the pure Al coatings were prepared under the different conditions of gas pressure and temperature. The in-flight particles velocity was measured by DPV-2000 system and the tensile strength of coatings on different substrates was also investigated. The results show that the in-flight particles velocity increases and the critical velocity decreases with the increasing of gas temperature, consequently, the deposition efficiency of Al increases to more than 95%. The deposition efficiency is also rising with the increasing of gas pressure because of the in-flight particles velocity increasing. Form the tensile strength results, it is shown that the adhesive strength of Al coatings is great depended on the substrate materials compared with influence of the gas temperature.