Titanium coatings were fabricated by the two-stage high velocity oxy-fuel spray process (Warm Spray) developed at NIMS, in which nitrogen gas is injected to the flame to control the oxidation of titanium powder during deposition. Spray particles’ in-flight velocity and temperature were measured by DPV2000 and correlated with the coatings properties such as oxygen content, porosity and adhesion strength. Oxygen concentration of the processing gas at the powder injection ports was also measured. The results show that higher nitrogen flow rate is very effective in lowering the oxygen content of the coatings to a level below 1 mass% but excessive nitrogen flow rate tends to increase porosity, i.e., there exists a trade-off between the oxygen content and porosity. The adhesion of the coatings increased with the particles’ velocity and exceeded 50 MPa for velocity over 600 m/s, but the temperature of the sprayed particles upon impact also had a significant effect on the adhesive strength.