The present paper is concerned with experimental study of the interaction between a wake, with injection at its begining,and a boundary layer. The wake is developed downstream a finite length and thickness plate inside an open-type wind tunnel test section while the boundary layer is developed over the wall of the test section. The measurements are carried out at Reynolds number 1.8 x 105 and injection to Main stream velocity ratios (A) of (0 < A< 0.7). In the experiments the mean velocity pro-files, the wall static pressure distrubtion and the local skin friction coefficient are measured. The results indicate that, for a certain velocity ratio, moving downstream from the trai-ling edge of the thick plate the wake decays while the bound-arey layer grows gradually. Also, the wake depth decreases,the wake width increases and the position of maximum velocity moves into the inner layer. On the other hand-at a certain distance from the trailing edge-as the velocity ratio increases the wall pressure coefficient, the momentum thickness Reynolds number and the shape factor decrease while the skin friction coeffic-ient increases. Also-as the velocity ratio increases the rate of wake decay, the wake center line velocity and the wake width increase while the wake depth decreases.