Abstract: Experimental research is carried out on a high subsonic tandem cascade, the rear blades of which have two different solidities. For test cascade A, the number of the rear blades is double the amount of B, and there are two locations of rear blades in cascade A, which is following the wake or the mainstream of the front, while the test cascade B only have the rear blades located at the wake of the front. It can be seen from the results that for test cascade A, the load and work capacity of the blades are higher when the rear blades are located near the wake than the mainstream. The larger solidity of rear blades would lead to a blockage in the channel. But cascade B have more uniform outlet flow. Optimizations design should be done about the locations of rear blades and profiles according to the use environment and purpose.