Microstructures and mechanical properties of cold sprayed coatings depend on the spraying parameters, such as, gas temperature, gas pressure, etc. Carrier gas is also one of the key parameters for engineering these coatings. Gas and particle velocities depend markedly on types of gases and their pressures. Therefore, coating quality drastically changed by carrier gas characteristics. Moreover, gas purity is directly associated with gas price and manufacturing cost and it is also important for industrial users. In contrast, small changes of purity do not strongly affect carrier gas velocity. However, the carrier gas and sprayed particles are possible to interact during spraying process. Moreover, the gas impurities can effect on the coating quality. In order to make clear the effects of gas composition on coating quality, this study investigated mechanical properties and microstructures of several cold-sprayed titanium coatings, which produced with different gas composition. Carrier gases were helium-based gases, with impurity levels up to 10% in volume. The results indicated that the gas composition strongly affected the mechanical properties of coatings, which it is also important factor of coating production.