Abstract: The blade-type swirlers have been used in many air engine combustors to control the primary airflow of flame tube and establish a strong recirculation zone. The losses produced by the swirler depend on stagger angle, pitch/chord ratio and passage area of blades.Some test results of the swirlers with different stagger angles, numbers of blades and flow areas are presented. A set of discharge characteristics and relations between loss coefficient and swirl number, stagger angle or blade number are provided. In addition, the correlation of loss coefficient to discharge coefficient of blade-type swirlers has been established. It is found out that the discharge coefficient varies from 0.6 to 0.9 for swirlers with different stagger angles. The correlation ψ=31.0（1.53s- 1） indicates that the selection of swirl number must retain the loss coefficient at an acceptable level （aerodynamically）.It can be seen from the test results that the blade loss is evidently smaller than the secondary expansion loss for a given combustor swirler. The value of the blade loss is about 18 percent of the total loss for a straight blade swirler with stagger angle varying from 68° to 70°.The tests have also proved that the twisted blade swirler is superior to the straight one from the aerodynamic point of view. But its manufacture is more complicated. Therefore, the straight blade swirlers （with stagger angle ≥45°） have been used in a large number of combustors.